This is roasted spaghetti squash tossed with cashew-based vegan pesto and topped with balsamic-marinated cherry tomatoes. It comes together in about an hour with one baking sheet, one blender, and one bowl — and the result is a genuinely satisfying dinner that doesn’t taste like it’s trying to be something else.
The technique that matters
The single most important step is getting the squash dry before you toss it with pesto. After you rake the flesh into strands, blot it firmly with a clean kitchen towel or a few paper towels. Spaghetti squash holds a surprising amount of water, and if you skip this, the pesto turns watery and slides right off. The second thing worth getting right is the pesto texture — blend the cashews long enough that the mixture is genuinely smooth, not gritty. A grainy pesto coats the strands unevenly. Thirty extra seconds in the blender makes a real difference.
Shopping notes
- Cashews: You need raw, unsalted cashews — not roasted. Roasted cashews change the flavor and won’t blend as smoothly. Soak them in cold water for at least two hours, or in boiling water for 20 minutes if you’re short on time.
- Nutritional yeast: This is what gives the pesto its savory, cheesy depth. Find it in the bulk section of natural food stores or near the condiments in most grocery chains. Brands vary in intensity, so taste as you go.
- Cherry tomatoes: Any variety works. A mix of colors looks good, but a single variety tastes just as good — skip the garnish hunt if it means an extra store trip.
- Balsamic vinegar: Use a standard supermarket balsamic, not an aged reduction. You want the acidity here, not sweetness.
Make-ahead notes
The pesto keeps well in an airtight jar in the fridge for up to five days. Press a thin layer of olive oil over the surface before sealing to slow browning. The roasted squash strands can be refrigerated separately for up to three days — store them unsauced so they don’t get soggy. Reheat the squash in a dry skillet over medium heat for a few minutes, then toss with pesto off the heat. The marinated tomatoes are best made the same day; they get watery overnight and lose their texture. The pesto also freezes well in an ice cube tray for up to two months — pop out a cube or two and thaw in the fridge the night before.
Mistakes to avoid
- Undercooking the squash: If the strands don’t pull away cleanly with a fork, the squash needs more time. Undercooked squash is dense and slightly bitter. Give it five more minutes and test again.
- Over-salting the pesto before tasting: Nutritional yeast already adds a salty, savory note. Season the pesto at the end, after blending, not before.
- Adding pesto while the squash is piping hot: Very high heat can make the olive oil in the pesto separate and turn greasy. Let the squash cool for two or three minutes before tossing.
- Skipping the lemon juice in the pesto: Without it, the cashew base tastes flat and heavy. The acid is doing real work here, not just adding brightness.
- Piling the tomatoes on too early: If you add the balsamic tomatoes while everything is still hot, they release extra liquid and water down the dish. Spoon them on right before serving.
Spaghetti Squash with Pesto and Cherry Tomatoes
Equipment
- Oven
- Baking sheet
- Food processor or blender
- Chef's knife
- Spoon or fork
- Mixing bowl
Ingredients
Roasted Spaghetti Squash
- 1 medium spaghetti squash about 2 to 2.5 lbs, firm and golden yellow
- 2 tablespoons olive oil extra virgin for flavor
Vegan Basil Pesto
- 2 cups fresh basil leaves preferably organic and freshly picked
- ½ cup raw cashews soaked in hot water for 15 minutes for creaminess
- 2 tablespoons nutritional yeast adds cheesy flavor
- 2 cloves garlic fresh and minced
- â…“ cup olive oil extra virgin, cold-pressed
- 1 tablespoon lemon juice freshly squeezed
- ¼ teaspoon sea salt adjust to taste
Cherry Tomato Topping
- 1 pint cherry tomatoes halved, preferably heirloom varieties for color and sweetness
- 1 tablespoon balsamic vinegar
- 1 tablespoon olive oil
- â…› teaspoon sea salt
Instructions
- Preheat the oven to 400°F (200°C). Cut the spaghetti squash in half lengthwise and scoop out the seeds with a spoon.
- Drizzle the inside of each half with olive oil and sprinkle lightly with salt. Place squash cut-side down on a parchment-lined baking sheet. Roast for 40–45 minutes until the flesh is fork tender and pulls apart easily into strands.
- While the squash is roasting, prepare the vegan pesto. In a food processor, add basil, soaked cashews, nutritional yeast, garlic, lemon juice, and salt. Pulse until finely chopped.
- With the motor running, slowly drizzle in olive oil until a creamy pesto forms. Scrape down the sides as needed.
- In a bowl, mix halved cherry tomatoes with balsamic vinegar, olive oil, and a pinch of sea salt. Set aside to marinate briefly.
- Once the squash is cooked, let cool for 5 minutes. Use a fork to shred the flesh into long spaghetti-like strands and transfer to a large mixing bowl.
- Toss the warm squash strands with the pesto until evenly coated. Taste and adjust seasoning if needed.
- Top with marinated cherry tomatoes. Finish with a drizzle of olive oil and extra basil leaves if desired.
Notes
- Add red pepper flakes to the pesto for a spicy kick.
- If cashews are unavailable, use pine nuts or shelled sunflower seeds as a substitute.
- Pesto can be made ahead and stored in the fridge for up to 5 days.
- Use multicolored heirloom cherry tomatoes for a more visually captivating presentation.
Nutrition
Frequently asked questions
Can I use a different nut instead of cashews in the pesto?
Yes — raw sunflower seeds are the most practical swap and keep the pesto nut-free. Blanched almonds also work, though the pesto will be slightly less creamy and may need a splash more olive oil or water to blend smoothly.
How do I know when the spaghetti squash is done roasting?
The flesh should pull into long, separate strands easily when you drag a fork across it. If the strands are clumping or tearing rather than separating, it needs more time in the oven.
My pesto turned out too thick — how do I fix it?
Add cold water one tablespoon at a time while the blender is running until you reach a saucy, spoonable consistency. Water works better than extra olive oil here because it thins without making the pesto heavy.
Can I make this without a high-speed blender?
A standard blender works if you soak the cashews for the full two hours and blend in longer bursts, scraping down the sides often. A food processor will give you a chunkier, more rustic pesto — still good, just not as smooth.
What to cook next
- Macadamia Nut Pesto Pasta
- Mediterranean Orzo Artichoke Salad
- Baked Ratatouille with Herb Oil
- Mediterranean Lentil Power Bowl