1. Cut the Feta into small cubes and marinate it in olive oil, Herbes de Provence, and Espelette pepper. Reserve in the refrigerator. Cut the peppers in half and remove the seeds. Place them on a baking sheet lined with parchment paper. Bake at 230°C and cook until the skin starts to blacken. Remove them from the oven and wrap them in aluminum foil. After a few minutes, you can easily remove the skin. Cut into strips and set aside. Lower the oven temperature to 190°C.
2. Blanch the tomatoes: briefly plunge the tomatoes into boiling water, then rinse them under cold water. You can easily remove the skin. Cut them into small pieces. Wash and dry the zucchini and eggplants, then also cut them into cubes. Set aside.
3. Peel and chop the onions and garlic. In a pan, sauté the onions and garlic without letting them brown. Add the eggplants and cook for 5 minutes while stirring. Do the same with the zucchini and tomatoes one by one. Finally, add the peppers. Cook over low heat for 30 minutes. Taste and adjust the seasoning.
4. Prepare the Parmesan cream: in a saucepan, mix the cream and milk. Bring to a boil and let it reduce by half. Add the grated Parmesan and mix well to obtain a smooth cream. Set aside.
5. Prepare the lasagna dish: spread a layer of Parmesan cream on the bottom of the dish, then arrange the pasta sheets to completely cover the dish. Add a layer of vegetables, sprinkle with drained Feta cubes and chopped fresh basil. Then cover with Parmesan cream and repeat until the dish is filled. Finish with a layer of pasta and cover the pasta with grated Emmental cheese. Bake for 30 minutes.
6. Your vegetarian lasagna is ready, serve it as a main dish with a green salad or, for the more indulgent, with white meat or grilled fish.