sentence: melt butter in a pan sentence: add onions shallots and garlic to the pan sentence: add the beef to the pan sentence: add the tomatoes and stock to the pan sentence: mash the potatoes with butter sentence: add milk to the potatoes and stir sentence: add salt and pepper to the pot and stir sentence: mix an egg yolk with the mashed potatoes sentence: mix an egg with the beef and onions sentence: place the meat in the dish sentence: place the mashed potatoes on top of the meat sentence: brush butter on the potatoes sentence: sprinkle bread crumbs and thyme on top sentence: bake the dish in the oven