Sauté the Aromatics: Heat the olive oil in a large pot or Dutch oven over medium heat. Add the onion, carrots, and celery. Cook until softened, about 5-7 minutes. Add the minced garlic and cook for another minute until fragrant.

Bloom the Spices: Stir in the smoked paprika, cumin, and dried thyme. Cooking the spices for a minute before adding liquids awakens their flavor.

Combine and Simmer: Pour in the vegetable broth and diced tomatoes. Add the rinsed lentils and nutritional yeast. Bring the soup to a boil, then reduce the heat to low, cover, and let it simmer for 30-35 minutes, or until the lentils are tender.

Finish and Serve: Stir in the fresh spinach and cook for 2-3 minutes until it wilts. Season with salt and pepper to your liking. Serve hot.