Start by cutting the aubergines in half. Cut their flesh into cubes and add the olive oil, salt, black pepper and oregano. Bake for 30-40 minutes at 180C.
Meanwhile, prepare the filling. Pour the olive oil in a non-stick pan. Once warm, add the onion. After 1-2 minutes add the garlic and mushrooms. Cook for 4-5 minutes and then add the tomato sauce. Let your sauce make. If you think it is necessary, add a little water.
Finally, add the grated vegan feta cheese. Set aside.
Once the aubergines are done, take them out of the oven and remove their flesh. Put it in the minced mushrooms. Stir. Fill the aubergines.
Now is the time to prepare the béchamel. Put the olive oil and flour in a saucepan. Stir until smooth. Slowly add the milk. Stir at the same time. Add salt, black pepper and nutmeg and continue stirring until the béchamel thickens.
Spread it on your aubergines and put it back in the oven for about 20 minutes. Take it out of the oven and enjoy.