Heat 300 ml of whole milk with 1/4 of an onion (with 2 cloves inserted) in a pot. Do not let it boil.

In a pan, melt 25 g of butter and add 25 g of wheat flour. Mix on low heat until a paste forms.

Remove the onion with cloves from the milk and slowly add the milk to the roux, stirring constantly until thickened.

Season with salt and nutmeg to taste.

Finely chop 60 g of mushrooms, 1 clove of garlic, and 1/4 of an onion.

In a pan, heat a splash of olive oil and 1 tbsp of butter. Sauté the chopped mushrooms, garlic, and onion until soft.

Add the sautéed vegetables to the bechamel sauce and mix well.

Add 60 g of mozzarella cheese and 3 tbsp of parmesan cheese to the mixture. Stir until the cheese is melted and well combined.