Cook the lentils: Place the rinsed lentils in a pot with plenty of water. Bring to a boil, then reduce heat and simmer uncovered for 15-20 minutes until tender but not mushy. Drain and set aside.
Saute the aromatics: Heat the olive oil in a large pot over medium heat. Add the onion, carrots, and celery and cook for 6-8 minutes until softened. Add the garlic and cook for another minute until fragrant.
Build the flavor: Stir in the tomato paste, bouillon powder, oregano, and thyme. Cook for about 2 minutes, stirring to coat the vegetables.
Simmer: Add the cooked lentils and crushed tomatoes. Bring to a simmer, cover, and cook over low heat for 5-10 minutes for the flavors to come together.
Season: Taste and season with salt, black pepper, nutritional yeast, and a small dash of sweetener to balance the acidity. Adjust until it tastes right to you.
Serve: Toss with your cooked pasta of choice and top with fresh basil and lightly toasted sunflower seeds.