Pork and mushroom casserole

650g pork shoulder, trimmed, cut into 2cm cubes 1D2 cup plain flour salt and pepper 1 tbsp each butter and pure olive oil 1 stalk celery, peeled, chopped 1 medium onion, peeled, diced 1 clove garlic, part-crushed, peeled, finely chopped 20 button mushrooms, stalks trimmed, wiped with damp cloth 1 sprig fresh thyme, or 1 tspn dried 1D2 cup white wine 3D4 cup chicken stock 1 egg yolk 1D4cup cream
Toss pork with flour and a little salt and pepper. Place in a strainer over a bowl and shake so each cube has a fine coating. Heat butter and oil in a casserole dish. As soon as the butter stops foaming, add the pork. Brown on all sides, then remove. Add the celery and onion plus a little more oil and cook, stirring, until the onion just begins to colour. Stir in the garlic, cook for 30 seconds more then remove all the vegetables. Replenish the oil and brown mushrooms on both sides. Add the wine and stir in all the browned bits at the bottom of the pan, return the meat and vegetables plus the thyme, then pour the stock over the top. Place on a very slow element and cook for 11D2 hours, stirring and adding a little more stock from time to time if necessary. When meat is tender, remove everything but the cooking liquid and keep warm. Whisk egg yolk and cream together with fork. Take the casserole off the heat and stir the egg and cream mixture into the cooking liquid until it thickens. Don't overheat, or you will end up with scrambled eggs. Check the seasoning, pour over the meat and vegetables and serve.
Serves 4