Let’s break down the process into easy-to-follow steps.

Step 1: Sauté Vegetables. Heat the olive oil in a large pot over medium heat. Add the diced onions, chopped carrots, and chopped celery. Sauté for 5 minutes, until the vegetables start to soften.

Step 2: Add Mushrooms and Garlic. Add the minced garlic and sliced mushrooms to the pot. Cook for another 5 minutes, until the mushrooms release their moisture and start to brown.

Step 3: Add Tomato Paste and Spices. Stir in the tomato paste, dried thyme, and smoked paprika. Cook for 1 minute, stirring constantly, to release the flavors.

Step 4: Add Lentils, Tomatoes, Broth, and Bay Leaf. Add the rinsed lentils, diced tomatoes, vegetable broth, and bay leaf to the pot. Bring the mixture to a boil.

Step 5: Simmer. Once boiling, reduce the heat to low and simmer for 25-30 minutes, or until the lentils are tender.

Step 6: Season and Add Greens (Optional). Season the stew with salt and pepper to taste. If using, add chopped kale or spinach and cook for an additional 5 minutes, until wilted.

Step 7: Remove Bay Leaf and Garnish. Remove the bay leaf before serving. Garnish with fresh parsley, if desired.

These steps are very simple.