Preheat the oven to 200C.
Fry onion and garlic in a casserole dish add the butter then add the left-over beef. Next add the left over vegetables, stock and wine.
Mix the flour into a paste with a little cold water, add to the pan and simmer for 10, season to taste.
Stir in the fresh thyme, then arrange the potatoes on top.
Cover with a lid and cook in the oven for one hour.
Remove the lid and increase the heat to 200C/400F/Gas 6 for 30 minutes.