Roast beef is a high-protein lean meat that makes an excellent dinner entree or sandwich for lunch. Most people think beef must be cooked in a conventional oven for the best taste. However, it is possible to use a microwave to cook your top round roast beef. Just follow a few simple instructions to prepare a tasty meal in your microwave.

Prepare the roast beef by defrosting in the refrigerator or at room temperature for two to three hours. Add herbs and spices for flavor.

Place the roast beef inside the microwave-safe roasting bag. Seal the bag loosely to allow for ventilation and place this on top of a microwave-safe plate.

Place the roast in the microwave, allowing a few inches of space on top and on the sides of the roast.

Cook for the time frame recommended based on the wattage of your microwave. Approximately 10 minutes per pound of meat is suggested, but consult your microwave owner's manual to determine wattage.

Remove the roast beef from the microwave and insert the meat thermometer to check the internal temperature. At least 170 degrees Fahrenheit is preferable. If it has not reached this temperature, place the roast back in the microwave and cook until it does.