Baked Ratatouille Herb Oil

Baked ratatouille is summer vegetables — eggplant, zucchini, tomatoes, and peppers — sliced thin, layered over a fennel-scented tomato sauce, and roasted until tender. The herb oil drizzled on at the end is what makes it worth the effort: bright, fresh, and sharp against the sweet roasted vegetables. Make it the centerpiece of a meal, not a side dish, and it will actually fill you up.

The short version of why this works

Two things matter here. First, the base sauce does real work — it keeps the bottom layer of vegetables from drying out and gives the whole dish a savory foundation that plain sliced vegetables can’t build on their own. Don’t rush it or thin it out. Second, uniform slice thickness is not about looks; it’s about even cooking. Thicker slices stay firm and underdone while thinner ones turn to mush beside them. A mandoline or a steady hand with a sharp knife gets you consistent results. Everything else is just assembly.

Substitutions that actually work

• Zucchini: Yellow summer squash works identically — same water content, same cook time.
• Eggplant: If you can’t find globe eggplant, Japanese eggplant slices are narrower but cook the same way. Avoid large, seedy eggplants; they release too much water.
• Fresh tomatoes for the sauce: A 14 oz can of crushed tomatoes is a reliable substitute when fresh tomatoes are out of season and flavorless.
• Fennel in the base: If fennel isn’t available, a small pinch of fennel seeds added to the sauce gives you the same anise note without buying a whole bulb.
• Herb oil herbs: Flat-leaf parsley or tarragon can stand in for any herb in the oil — skip the garnish if you’re already using fresh herbs in the oil, not worth the extra dish.

Keeping and reheating

Leftovers keep well in an airtight container in the fridge for up to 4 days. The flavor actually improves overnight as the layers settle. Reheat individual portions in a 350°F oven for 10–12 minutes to keep the edges from going soggy — the microwave works in a pinch but softens the texture noticeably. For longer storage, freeze in a single layer on a baking sheet first, then transfer to a freezer bag; it holds for up to 2 months. Thaw overnight in the fridge before reheating. Store the herb oil separately and add it fresh after reheating, since it loses its brightness once warmed.

Troubleshooting

• Watery liquid pooling in the dish: Eggplant and zucchini release moisture as they cook. If you see significant pooling halfway through, carefully tilt the dish and spoon off the excess. Covering the dish too tightly early on traps steam — leave it uncovered for at least the last 20 minutes.
• Vegetables browning on top before they’re cooked through: Lay a sheet of parchment loosely over the top for the first half of baking, then remove it to let the edges caramelize. Foil works too but can stick to the top layer.
• Base sauce burning on the edges: This usually means the sauce was spread too thin near the rim. Keep it at least half an inch from the edge of the dish, or use a slightly smaller baking dish so the sauce stays thick.
• Herb oil turns brown quickly: Blend or mix the herb oil just before serving. If you make it more than a few hours ahead, press plastic wrap directly onto the surface of the oil to limit air contact and refrigerate it.
• Dish feels light on protein after plating: Serve it over a scoop of white beans warmed in olive oil and garlic, or alongside a thick slice of toasted bread spread with hummus. Either option rounds out the meal without competing with the vegetables.

Cook ModePrevent your screen from going dark

Baked Ratatouille with Basil–Parsley Herb Oil

Mary Jackson

Baked ratatouille layers thin rounds of eggplant, zucchini, yellow squash, and tomato over a roasted tomato–pepper sauce, then bakes low and slow until the vegetables are tender and lightly caramelized. A bright basil–parsley herb oil is drizzled over just before serving. Plan on about 90 minutes start to finish, making it a solid choice for a relaxed weekend dinner.

No ratings yet

Print Recipe Pin Recipe

Prep Time 35 minutes mins

Cook Time 55 minutes mins

Total Time 1 hour hr 30 minutes mins

Course Main Course

Cuisine Mediterranean

Servings 6 servings

Calories 218 kcal

Equipment

• 12-inch oven-safe skillet or 2-quart baking dish
• Mandoline (optional but recommended for even slices)
• Chef’s knife and cutting board
• Colander
• Mixing bowls
• Measuring cups and spoons
• Parchment paper
• Aluminum foil or oven-safe lid
• Silicone brush or spoon

Ingredients

 

US CustomaryMetric

 

1x2x3x

To Prep the Eggplant:

• 1 medium globe eggplant about 1 lb; sliced into 1/8-inch-thick rounds; not peeled
• 1 tsp kosher salt for purging the eggplant

For the Tomato–Pepper Base Sauce:

• 2 tbsp extra-virgin olive oil good-quality, fruity oil
• 1 cup yellow onion, small dice from 1 medium onion
• 1 cup red bell pepper, small dice from 1 medium pepper
• ½ cup fennel bulb, finely diced optional but lovely anise note
• 4 cloves garlic, thinly sliced fresh, not jarred, for best aroma
• ¼ tsp crushed red pepper flakes adjust to taste
• 2 tbsp tomato paste double-concentrated if available
• 2 cups canned crushed tomatoes preferably San Marzano; about 16 oz
• 4 sprigs fresh thyme or 1 tsp dried Herbes de Provence
• 1 piece bay leaf remove before layering
• 1 tsp kosher salt plus more to taste
• ½ tsp freshly ground black pepper
• 2 tsp balsamic vinegar for brightness
• ½ tsp organic cane sugar optional, to balance acidity if needed

For the Layered Vegetables:

• 2 medium zucchini sliced into 1/8-inch-thick rounds
• 2 medium yellow squash sliced into 1/8-inch-thick rounds
• 4 medium Roma (plum) tomatoes firm; sliced into 1/8-inch-thick rounds
• 1 tbsp extra-virgin olive oil for drizzling over the layered vegetables
• 1 pinch kosher salt for seasoning layers
• 1 pinch freshly ground black pepper for seasoning layers

For the Basil–Parsley Herb Oil:

• 3 tbsp extra-virgin olive oil peppery, vibrant oil
• ¼ cup fresh basil leaves, finely chopped packed
• 2 tbsp fresh flat-leaf parsley, finely chopped
• 1 tsp lemon zest finely grated
• 1 clove garlic, grated microplane for a smooth finish
• 1 pinch kosher salt to season the herb oil

For Finishing & Serving:

• 1 tbsp capers, rinsed non-pareil capers preferred
• 1 pinch flaky sea salt to taste
• 1 pinch freshly ground black pepper to taste

Cook ModePrevent your screen from going dark

Instructions

 

• Read through the recipe before starting. Preheat your oven to 375°F (190°C). Lightly oil a 12-inch oven-safe skillet or a 2-quart baking dish.
• Pre-Salt the Eggplant (20 minutes): Slice the eggplant into 1/8-inch-thick rounds. Toss with 1 tsp kosher salt in a colander and let stand 20 minutes to draw out excess moisture and any bitterness. Rinse quickly and pat very dry with clean towels. This step improves texture so the eggplant bakes silky, not spongy.
• Start the Base Sauce (15–18 minutes): Warm 2 tbsp olive oil over medium heat. Add diced onion with a pinch of salt; cook, stirring, until translucent with a hint of gold at the edges, 5–6 minutes. Add bell pepper and fennel; sauté until tender and sweet, 4–5 minutes. Stir in garlic and red pepper flakes; cook 30 seconds until fragrant. Clear a spot in the pan, add tomato paste, and cook 2 minutes until brick-red and caramelized—this deepens the umami. Pour in crushed tomatoes, add thyme and bay, 1 tsp kosher salt, and 1/2 tsp black pepper. Simmer, stirring, until thick and glossy, 10–12 minutes. Off the heat, stir in balsamic (and optional sugar). Remove thyme sprigs and bay leaf.
• Sauce Base and Vessel: Spread the sauce in an even layer in your skillet or baking dish—it should just cover the bottom to cradle the vegetables without drowning them.
• Slice the Remaining Vegetables: Using a mandoline (or a sharp knife), slice the zucchini, yellow squash, and Roma tomatoes into even 1/8-inch-thick rounds. Pat tomato slices dry if especially juicy; even thickness ensures uniform cooking.
• Layer and Season: Arrange the eggplant, zucchini, squash, and tomato slices in a tight, overlapping spiral over the sauce, alternating colors for a mosaic effect. Drizzle with 1 tbsp olive oil and season lightly with a pinch of salt and pepper.
• Cover and Bake (40 minutes at 375°F/190°C): Cut a round of parchment to fit and lay it directly on the vegetables. Cover tightly with foil or a lid to trap steam. Bake until the vegetables are tender when pierced but still hold their shape, about 40 minutes.
• Uncover to Finish (12–15 minutes): Remove parchment and foil/lid. Continue baking uncovered until the top edges lightly caramelize and most surface moisture has evaporated, 12–15 minutes. For deeper color, broil 1–2 minutes, watching carefully to avoid scorching.
• Make the Herb Oil: In a small bowl, combine 3 tbsp olive oil, chopped basil and parsley, lemon zest, grated garlic, and a pinch of salt. Mash gently with a spoon to bruise the herbs and release their oils. If you don’t have a microplane, mince the garlic very finely to keep the oil smooth.
• Rest, Finish, and Serve: Let the ratatouille rest 10 minutes out of the oven to settle the juices. Drizzle with herb oil, scatter capers, and finish with flaky salt and a few grinds of pepper. Serve warm or at room temperature; the flavors bloom as it cools slightly.

Notes

Mary’s Tips:

• Select firm, glossy vegetables. Similar diameters make the shingled pattern tighter and the bake more even.
• No Mandoline? Use a sharp knife and take your time. Aim for even 1/8-inch slices; consistency matters more than speed.
• Boost umami by caramelizing the tomato paste until it darkens—this is the difference between a good and a great sauce.
• Convection ovens run drier; start checking 5 minutes earlier during the uncovered bake.
• Substitutions: Use Japanese eggplant in place of globe; swap thyme for Herbes de Provence; replace fennel with celery if needed. For nightshade sensitivity, omit tomato and use a bed of sautéed onions and summer squash only (flavor will differ).
• Oil-Light Approach: Brush vegetables with vegetable stock instead of oil, and finish with just a teaspoon of olive oil in the herb drizzle.

Nutrition

Calories: 218kcalCarbohydrates: 21gProtein: 5gFat: 15gSaturated Fat: 2gPolyunsaturated Fat: 2gMonounsaturated Fat: 10gSodium: 1007mgPotassium: 972mgFiber: 7gSugar: 13gVitamin A: 1812IUVitamin C: 78mgCalcium: 84mgIron: 2mg

Keyword Baked Ratatouille, Gluten-free, one-pan, Provençal, summer vegetables, Vegan

Tried this recipe?Rate this recipe !

Common questions

Do I have to salt the eggplant before assembling?

No, but it helps. Salting draws out excess moisture, which means less liquid pooling in the finished dish. If you skip it, pat the eggplant slices dry with a paper towel before layering — it’s a faster version of the same idea.

Can I make this ahead for a dinner party?

Yes — it’s actually better made a few hours in advance. Assemble and bake it fully, let it cool, then refrigerate. Reheat covered at 350°F for about 15 minutes before serving and add the herb oil fresh at the table.

What do I serve with this to make it a full meal?

Cooked white beans, lentils, or chickpeas alongside it add enough protein to make it genuinely filling. A grain like farro or crusty bread also works well to soak up the sauce from the base.

More plant-based recipes to try

• Mediterranean Lentil Power Bowl
• Smoky Spanish Chickpea Stew
• Mediterranean Orzo Artichoke Salad
• Vegan Paella Valenciana Recipe