Guinness Beef Pie

olive oil
1 kg stewing steak, well trimmed & cubed
2 large onions, chopped
2 medium-large carrots, diced
2 large rindless bacon rashers, sliced
2-3 tbsp plain flour
2 cups beef stock
1 tbsp tomato paste
1 heaped tbsp brown sugar
330 ml bottle Guinness
freshly ground salt & pepper
1 sheet frozen puff pastry
1 egg
2 tbsp milk
Heat oil in a large pot and seal beef to brown, in 3-4 lots. Remove meat and set aside. If needed, add a little more oil to pot together with onions, carrots and bacon. Gently saute for 5-10 mins until softened, stirring now and again. Add flour, mix well and cook for a few seconds. Then add stock, tomato paste, sugar, Guinness and seasonings, together with beef, and mix. Bring to the boil, turn heat down, cover and gently simmer for 1½ hours, adding more stock if needed. Preheat oven to 190°-200°C. Allow meat mixture to cool a little and then place in an ovenproof dish. Place pastry sheet on top and brush with egg wash (egg mixed with milk). Cook in oven for about 15 mins until pastry is golden brown and meat is piping hot.