First, prepare the TVP in vegetable broth according to the instructions on the package. Usually you have to soak it in hot water (for example from the kettle) for about 10 minutes. I like to use vegetable broth instead of water for more flavor. Then peel the potatoes and cut them into thin slices.
Wash and slice the eggplant and zucchini.
Heat some oil in a large flat pan and fry the eggplant and zucchini slices on both sides. Add some salt.
Use another pan, heat some oil, and pan-fry the potato slices on both sides. Cook them for 2-3 minutes on both sides. Set aside.
Alternatively, you could also prepare them in the oven. Preheat your oven to 350 °F. Line two baking sheets with parchment paper. Place the potatoes on one baking sheet and the eggplant and the zucchini on the other one. Toss with 2-3 tablespoons of olive oil and sprinkle with salt. Bake for 20 minutes.
In the meantime, prepare the vegan meat sauce. First, finely chop the garlic and the onion. Drain the soaked TVP. Heat some oil in one of the pans you used before, and cook the TVP for about 3 minutes on high heat. Then add the onions and sauté for another 3 minutes. Add the garlic towards the end. Then add the tomato paste, stir well and sauté for 2 minutes.
Deglaze with the red wine, let it evaporate.
Then add the chopped tomatoes. Season with oregano, cinnamon, allspice, cumin, nutmeg, salt and pepper.
Cook for 3 minutes on medium heat.
Then layer the vegetables, potatoes and sauce in a casserole dish. Start and finish with the sauce.
Preheat your oven to 350 °F. Then make the vegan béchamel sauce. Melt a tablespoon of vegan butter or margarine in a small saucepan. Once the margarine has melted, add a tablespoon of flour and stir well.
Add the unsweetened oat or soy milk and simmer for about 3 minutes until the sauce has thickened considerably. Stir in the nutritional yeast and season with salt, pepper, and nutmeg.
Pour the béchamel sauce on top and spread evenly.
Bake for 40-50 minutes until the top is nicely browned. Check after 30 minutes and cover the casserole dish with aluminum foil if it gets too dark.