Remove the stems of the brown mushrooms and wash them.
Wipe the brown mushrooms with a towel.
Place them in a tray lined with baking paper, stem (gill) side up.
Prepare a sauce in a bowl. First, squeeze in the juice from a lemon.
Chop finely 3 cloves of garlic and add over it.
Then, add some oil, butter, thyme, and season with salt and pepper. Mix gently all the ingredients.
Grease the brown mushrooms well with this prepared sauce.
Put the mushrooms on a tray and place it in the oven at 170° C for 25 minutes.
After 15 minutes, return the mushrooms and let them brown a little.
When they are ready, place them on a plate.
Sprinkle fresh chopped parsley over them and serve.