Red or green lentils simmer with aromatics and vegetables until thick, rich, and deeply savory in this straightforward soup. Spices like cumin and turmeric build the flavor base, and the whole pot is ready in roughly 40 minutes. It keeps well, so it's worth making a full batch for the week.
Rinse the lentils under cold water until the water runs clear. Set aside.
In a large pot, heat the olive oil over medium heat. Add the onion and sauté until it becomes translucent, about 5 minutes. Stir in the garlic and cook for another 30 seconds until fragrant.
Add the diced tomatoes, cumin, and smoked paprika. Cook, stirring occasionally, until the tomatoes soften, about 5 minutes.
Add the rinsed lentils and vegetable broth to the pot. Bring to a boil, then reduce the heat to a simmer. Cover and cook for 30-35 minutes, or until the lentils are tender.
Stir in the baby spinach and cook until wilted, about 3 minutes. Season with sea salt and freshly ground black pepper to taste. Stir in the lemon juice just before serving.
Notes
For a richer soup, consider adding a tablespoon of nutritional yeast for a hint of umami. If you prefer a thicker consistency, use an immersion blender to partially puree the soup before adding the spinach.