Шаг 1
Cut the meat into large serving pieces, season with pepper, add thyme sprigs, and leave in a warm place for 30 minutes. Dice three onions and slice the other three into rings. Grate the cheese. Fry the diced onions in olive oil until golden and transfer to a plate.
Шаг 2
Let’s prepare the sauce. In a heated pan, melt the butter, add flour, and cook over medium heat for about three minutes, stirring constantly. Gradually pour in the milk and stir to avoid lumps. If lumps form, strain the sauce. It will be very thick. Add cream and simmer for a few minutes.
Шаг 3
Remove the sauce from heat and after a minute, add the cheese, stirring thoroughly.
Шаг 4
Place foil on a baking sheet, grease with olive oil, and lay out the onion rings.
Шаг 5
Lightly salt the meat, unless the sauce is already salty enough. Place the meat in one layer on top of the onion rings, then add the fried onions on top.
Шаг 6
Pour the cheese sauce over the meat.
Шаг 7
Bake at 180°C. Cooking time depends on the meat — about one hour. Towards the end, reduce the oven temperature to 150°C. If the crust starts to burn, cover with foil.