VEGGIES: Add the 1/4 cup olive oil to a large cast iron pot or Dutch oven and heat over medium. Once shimmering, add in the 1 cup diced yellow onion, 1 cup diced carrots (no need to peel), and 1/2 cup diced celery. Cook, stirring frequently, for 5-7 minutes. Add in the 1 heaping tablespoon of garlic, stir, and cook for 1 minute. Add in the 1 cup diced potatoes (gain, no need to peel) and 1 cup diced sweet potatoes (I do peel these). Stir to coat everything in the oil and cook for 3 minutes.
SEASONINGS: Add in the 3 tablespoons tomato paste and all the seasonings: 2 teaspoons ground cumin, 2 teaspoons Italian seasoning, 1 teaspoon yellow curry powder, 1/2 teaspoon ground turmeric, 1/2 teaspoon paprika, and salt and pepper to taste. Stir, toasting the seasonings and coating all the veggies. Cook for 2 minutes. Add in the undrained fire-roasted diced tomatoes and undrained fire-roasted crushed tomatoes. Cook for 2-3 more minutes, stirring frequently, to bring out all the flavors.
LENTILS: Rinse the lentils in cold water in a fine mesh sieve. Add the 3/4 cup lentils, the 32- ounce container of vegetable broth, and 1 and 1/2 cups chicken stock (or additional vegetable broth) into the pot. Stir in the 2 bay leaves.
COOK: Increase the heat and bring the soup to a boil. Once boiling, you'll see some bubbles or froth at the top of the pot. Skim this off with a spoon and discard. Stir the soup, and then reduce the heat to medium low, so the soup is gently simmering. Partially cover the pot with a lid, leaving some room for steam to escape. Cook for 25-30 minutes or until lentils are tender (they should still hold their shape).
OPTIONAL (CREAMIER TEXTURE): Transfer 2 cups of the soup to a high powered blender. Securely fasten the lid and blend until smooth (watch out for steam!). Pour the blended soup back into the pot and stir. We occasionally do this, but also enjoy the texture of all the veggies -- up to you what you prefer!
FINISHING: Remove the pot from the heat and add in 1/2 teaspoon lemon zest and 1 tablespoon lemon juice. Taste and adjust seasonings; add additional lemon juice if desired, salt and pepper if needed, and/or a pinch of red pepper flakes. Stir in the 1/3 cup freshly chopped parsley.
SERVE: Serve while hot. Top individual bowls with freshly grated Parmesan cheese. Leftovers will keep (stored properly in an airtight container) for about 4-5 days in the fridge.