Peel the potatoes and cut them into slices using a mandolin.
Line a baking sheet with parchment paper. Sprinkle with 3 tbsp of breadcrumbs and arrange the potatoes in rows, the rounds overlapping slightly on each side so that there are no gaps. Cover the entire baking sheet. Sprinkle with the rest of the breadcrumbs and a pinch of salt and bake at 360°F for 25-30 minutes. The potatoes should remain soft and slightly crispy.
For the sauce: rehydrate the protein by letting them cook for ten minutes in a vegetable broth. Drain and squeeze well to release all their water. Leave in colander until use.
Now, chop the celery into fine pieces, the carrot, the onion and the garlic. Pour into a sauté pan with 2 tbsp of olive oil and sauté for a few minutes until tender.
Add the protein with the paprika, nutmeg, cinnamon, bay leaf and soy sauce.
Season with salt and pepper; mix well over high heat for about ten minutes. Blend the peeled tomatoes into a smooth sauce and pour over the soy protein. Let simmer covered for 20 minutes, until the sauce thickens.
Prepare the spinach: pour 2 tbsp. at s. of olive oil and 2 peeled garlic cloves in a large sauté pan or pot. Add the washed and drained spinach. Season with salt and pepper.
Cook covered for ten minutes. At the end of cooking, remove the garlic and add in the vegan cashew cheese.
To assemble the dish; place the potatoes and their baking paper flat on the work surface.
Spread all the sauce evenly over the potatoes, leaving the edges free. Cover with spinach-vegan béchamel sauce that you have prepared.
Using the baking paper, roll the potato sheet over the filling lengthwise. Start by rolling one end, then fold the other end over the roll (it will be easier).
Once well rolled up in parchment paper, wrap everything in foil in a large aluminum foil, which will keep the roll tight during cooking. Bake in an oven at 440°F for 15 minutes.
Cut into slices and serve hot. Enjoy your diner!