In a large pot or Dutch oven, heat 2 tablespoons of olive oil over medium heat. Add 1 diced onion and 2 minced garlic cloves, sautéing for about 3-4 minutes until the onion becomes translucent and fragrant.

Stir in 2 chopped carrots, 2 chopped celery stalks, and 1 chopped bell pepper to the pot. Sauté for an additional 5-6 minutes.

Sprinkle in 1 teaspoon of cumin, 1 teaspoon of paprika, and 2 bay leaves. Stir the spices into the vegetables, cooking for about 1-2 minutes.

Add 1 cup of rinsed lentils, 1 can of diced tomatoes, and 4 cups of vegetable broth to the pot. Stir and bring the mixture to a boil, then reduce the heat to low and cover the pot.

Let your stew simmer gently for about 30 minutes, stirring occasionally.

In the final moments, stir in 2 cups of chopped spinach or kale, along with salt and pepper to taste. Allow the greens to wilt for about 2-3 minutes.

Ladle the warm stew into bowls, garnishing with fresh herbs if desired. Serve hot.