Sometimes known as the beef round tip roast, the sirloin roast is a lean cut of meat that's perfect for stir-frying—though it's not necessarily the most budget-friendly stir-fry option. After cutting the roast into thin strips, the stir fry sirloin cooks quickly in a wok or skillet at high temperatures. The high-heat cooking method ensures that the roast remains moist and tender. Fill out the rest of your stir fry with thinly cut veggies such as carrots, bell peppers, onions, broccoli and mushrooms for a satisfying and complete meal.
Place the roast in the freezer for 20 to 30 minutes. This short trip to the freezer will make the beef firmer and easier to slice. Not sure how to slice a sirloin tip roast? Using a sharp chef's knife, slice the roast against the grain into 1/8-inch thick slices. Make sure the slices are a uniform size, so they cook evenly.
Heat a small amount of oil in a large skillet or wok over medium-high heat. When the oil begins to shimmer, add the beef strips. Cook the beef in batches, about half a pound at time, to ensure even cooking. Overcrowding the pan will cause the beef to steam and you won't achieve that coveted nicely-browned exterior.
Stir-frying is a quick, high-heat cooking method, so be sure that the pan and oil are hot before adding the beef strips. If you're cooking several batches of beef, allow the pan and oil to heat up between batches.
If necessary, add more oil to pan in between batches. Stir the beef frequently to encourage even cooking. Fry the beef slices until they are browned and cooked through, about 3 to 5 minutes. Always cook whole cuts of beef to a minimum internal temperature of 145 degrees Fahrenheit to ensure safe consumption.
If you wish, you can marinate the beef beforehand for an ultra-flavorful stir-fry. You can use your favorite store-bought marinade, or make your own using a combination of Asian-inspired ingredients like lime juice, soy sauce, rice vinegar, garlic and ginger.
Add the roast to the marinade after cutting it into thin strips. Because of the strips' small size, they should be marinated for no more than 2 hours. Make sure the beef is thoroughly drained of the marinade before frying to encourage quick cooking and even browning.
Cook the sirloin strips and vegetables separately, then combine in the skillet and cook for a few moments more to ensure everything is nice and warm.