Not something you often see in restaurants, although miroton de bœuf sometimes pops up on bistro menus, especially in Lyon.
The recipe calls for thinly sliced leftover roast beef or boiled beef cheeks (joues), as in joues de boeuf en miroton, topped with a sauce made of onions browned in plenty of butter, with flour, white wine and vinegar, then sprinkled with breadcrumbs and baked.
Also spelled mironton.
Image by mammy