Beef and Guinness pie

Heat oil in a saucepan over a high heat.
Brown meat in batches, then remove from the saucepan and place meat in a greased ovenproof dish.
Add onions, carrots and potatoes to the dish. Sprinkle with peppercorns.
Mix together the Guinness, beef stock and tomato paste in a saucepan. Bring to the boil, then reduce heat to simmer.
Mix cornflour with a little cold water, then stir into the hot mixture.
Cook, stirring, until mixture has thickened. Stir in thyme and salt to taste.
Pour gravy over the meat and veggies.
Cut pastry into a square or rectangular shape, so that the side of the pastry will overlap the sides of the baking dish.
Bake in preheated oven for 40 minutes, or until golden.