Roast beef

I love this roast, it is easy to make, this recipe is the first that I made to cook a roast beef, 40 years ago, I kept it and I always redo the pleasure.Cooking is for a cooked roast.Chili sauce is not necessary, sometimes I put and other times not.1 internal round about 1.5 kg roast¼ cup butter mou(60g))2 c.soupe of mustard dry1 onion into thick slicespepperpinch of steak spice1 packet of Knorr prepared Demibeurre manié approximately 3 c.soupea bit of sauce (optional) Chileabout 5 cups (1 liter 250ml) hot water with 3 tea bags, infuse for well bodied2 c.soupe of bovril concentrated beefMix butter and mustard. Coat the roast (all red parts).Place in a baking dish. Put on the onion rings, pepper and sprinkle with steak spice.Put in the oven Preheat to 350 f. (180 C) and bake for 30 minutes.In a bowl place the tea, add the bovril, Chile sauce and mix.After 30 minutes of cooking add a little liquid to tea in the dish and return to the oven for another 1 hour basting from time to time and adding liquid if necessary.Remove the roast from the oven, wrap in paper aluminium, let stand.Add the remaining liquid to the baking dish and well scrape to get all the juices.Pass through a sieve and then degrease, put in a saucepan, add Demi-Glace sauce whisk and mix well.Bring to a boil, stirring and boil a little.Pepper and salt to taste.Add beurre manié a little at a time, stirring with a whisk