Classic Wellington is beef baked in puff pastry. I suggest trying the mushroom filling option. For my taste, it is in no way inferior to the original version.
Wash and dry the mushrooms. Separate the champignon caps from the legs. Pinch the mushrooms between two cutting boards and press down until they flatten. This is done to remove excess moisture from the mushrooms.
Preheat a skillet over medium heat. Fry the mushrooms without oil for a few minutes until they are well browned. Season with salt, pepper and Italian herbs. Then pour in the olive oil. Add sliced onion rings. Fry the mushrooms and onions until cooked through. Drain the excess liquid from the mushrooms.
Grind half of the fried mushrooms with walnuts and garlic in a meat grinder.
Add the second part of the mushrooms to the resulting mushroom mince, mix.
Roll out the dough into a rectangular layer 2 mm thick. Place the filling in the center. Give it a rectangular shape.
Cover the filling with one half, tuck the edges of the dough, then wrap the other half. Cut off excess dough with a knife.
Combine melted coconut oil, Jerusalem artichoke syrup, and soy milk.
Lubricate the roll with the resulting mixture. Refrigerate for 5-10 minutes. Then cut diagonally into the cake without cutting through the dough to the end. Bake the pie in an oven preheated to 190 degrees for 35-40 minutes.