Prepare the lentils: Cook 200 g of red or green lentils according to package instructions until al dente.
Sauté the onion and garlic: In a large pot or pan, heat some oil and sauté the chopped onion and garlic until fragrant.
Add the vegetables: Add the chopped carrot and celery and sauté for about 5-7 minutes until soft.
Toast the tomato paste: Add the tomato paste and briefly roast it.
Combine lentils and sauce: Add the cooked lentils, 800 g crushed tomatoes, one cup vegetable broth, and your favorite herbs (oregano, basil, thyme). Season with salt, pepper, paprika, and cumin. Let the sauce simmer for at least 20-30 minutes to blend the flavors.
Prepare the vegetables: Wash 500 g of fresh spinach, briefly steam it, and squeeze out excess water. Roughly chop it. Slice 1-2 zucchinis and/or 1 eggplant into thin slices. Optional: you can briefly sauté these in a pan.
Make the creamy layer: Blend 400 g of firm silken tofu or drained firm tofu with 2 tablespoons of lemon juice, 3 tablespoons of nutritional yeast, 1-2 chopped garlic cloves, a pinch of nutmeg, salt, and pepper until creamy.
Preheat the oven: Preheat the oven to 180°C (356°F). Lightly grease a large baking dish (approx. 25×35 cm).
Layer the lasagna: Start with a thin layer of tomato-protein sauce on the bottom of the dish. Place a layer of lasagna sheets on top, spread about half of the creamy