Step 1: Heat the olive oil in a large Dutch oven or heavy-bottomed pot over medium heat. Add the chopped onions, carrots, and celery. Sauté for 8-10 minutes, or until the vegetables are softened and the onions are translucent.
Step 2: Add the minced garlic and cook for another minute until fragrant, being careful not to burn it. Stir in the dried thyme, cumin, smoked paprika, and bay leaf. Cook for 30 seconds, allowing the spices to toast and release their aromas.
Step 3: Pour in the vegetable broth and the crushed tomatoes. Add the rinsed brown or green lentils. Bring the mixture to a boil, then reduce the heat to low, cover, and simmer for 25-30 minutes, or until the lentils are tender. Stir occasionally to prevent sticking.
Step 4: Once the lentils are tender, remove the bay leaf. Season the soup generously with salt and black pepper to taste. If you prefer a slightly thicker soup, you can mash a small portion of the lentils against the side of the pot with a spoon.
Step 5: For a fresh finish, stir in the fresh chopped parsley just before serving. A squeeze of fresh lemon juice at the end can also brighten the flavors beautifully.
Step 6: Serve hot with crusty bread, a side salad, or your favorite accompaniments. Enjoy your homemade hearty lentil soup!