I have a recipe for about a pound and a half of topside but I expect a pound would do.
Cut the meat into about 6 thin(ish) slices, then spread then with about a teaspoon of mustard, and a couple of ounces of chopped mushrooms, then roll up the slices carefully and secure the joins with some cocktail sticks.
Melt an ounce of butter in a pan, add a small chopped onion, and a couple of rashers of bacon and fry for a couple of minutes until softened, stir in 2 tablespoons of flour and cook for a further minute, gradually add in the contents of an 800g tin of chopped tomatoes and simmer gently until the sauce has thickened a little. Remove from the heat and sieve the sauce, then return to the pan and add some chopped parsley and a pinch of sugar.
Pour over the beef rolls (which you have already put into an ovenproof dish, cover with some tinfoil and Cook in the oven (180c 350f Gas 4) for an hour, turning the rolls occasionally. Remove the cocktail sticks before serving. Does this help?