A “rump roast” can actually refer to any of several distinct cuts of beef, but all have some characteristics in common. Rump roasts are lean but still offer a fair amount of marbling (fat distributed evenly through the muscle tissue, contributing to juiciness and flavor when cooked), but you shouldn’t expect the tenderest meat you’ve ever had. For this reason, a little special attention is required when cooking it to prevent it from getting to the table tough, which generally means using low heat for a long time. Another solution is to slice it very thinly, across the grain: most roast beef you’ll find on sandwiches, at buffets and delis are from rump roasts.
Roasting It (About 1 ½ Hour)
Probably the most traditional preparation method, this takes little preparation and yields a delicious result. Simply slice enough carrots, onions and celery to make a little bed on the roasting tray and add half a cup of water. For maximum flavor, rub the roast with salt, pepper and any spice mix you like, get a heavy skillet very hot, and quickly brown the outside. Place on the veggies, and stick in a 160°C (300°F) oven.
How long it takes to get to medium rare depends on the size of the roast; the best way is to use a meat thermometer to determine when the middle has reached 55°C (130°F). Once this is done, place the meat and vegetables on a serving tray, cover with foil and allow to rest. Place the roasting tray on the stovetop and add liquid (stock, wine), a tablespoon of flour and aromats to make a gravy.
Braising It (About 2 Hours)
Cooking slowly in liquid is a wonderful way to tenderize more muscular cuts of any meat while imparting extra flavor. It’s possible on the stove, but doing it in the oven prevents complications.
As above, you will season and brown the meat first. Then, just toss it into a deep baking tray or crockpot, add about 1 cup each of red wine and beef stock, along with garlic, rosemary or whatever you prefer. Cover with the crockpot lid or foil, and bake at 160°C (320°F) for about an hour and a half. When it has rested, you should be able to serve it in slices 2cm (1”) thick without your dinner guests needing axes to cut it.
Marinate It (About 12 Hours)
The main purpose of marinating beef is to improve the flavor, not tenderizing it. Still, marinades containing ingredients such as pineapple or yogurt (really) can help soften meat. Since the marinade works mainly on the surface of the meat, you could ask your butcher to prepare your roast as a roll.
After marinating the cut in the fridge overnight, you can pretty much roast it in the normal way.