top sirloin
2 steaks

heat - 4 seconds is medium heat

10-12 minutes

cook to 145 (medium rare)

stick thermometer in side, not top to determine temperature

turn once

Finally, standing time is a must when cooking any solid cut of beef. As the beef is heated, water is forced toward the center of the piece as well as evaporating from the edges. This water will be easily squeezed out of the beef as pressure is applied with a knife. By covering the beef to retain heat and letting it stand for 5-10 minutes after cooking, the water will redistribute throughout the cut so it harder to squeeze out water from the pressure of cutting. 

For stir frying, flank, top round, and sirloin steak are good. These cuts are best cooked quickly, and since elastin is broken because the meat is cubed, they are more tender.

trim fat off

BROILING: This is the indoor cousin of grilling. Broiling by direct heat in an oven is good for tender cuts that are thinner, such as top loin steak, sirloin or tenderloin steaks, or any kind of thinner lamb or pork chop. It also can be used for less tender cuts, like top round steak or flank steak, that have been marinated to tenderize them. Use a broiler pan with a rack in it; meat usually is turned once during broiling. 
The thicker the meat the farther from the broiler it should be cooked. For cuts 3/4- to 1-inch thick, cook 2 to 3 inches away; for cuts 1 to 2 inches thick, cook 3 to 4 inches from the heat.