Tortillas, sour cream, grated cheese and lettuce to serve
Coat beef strips with olive oil, sprinkle with ground cumin and sweet paprika, season well with salt and pepper. Preheat a non-stick pan to moderately-hot. Keep the heat at moderately high.
Cook the beef in 3 batches. Cook the first side until the first sign of moisture appears on the uncooked side, turn and cook the other side of the beef strips. Remove each batch and set aside.
Add onion and capsicum to the pan, cook for 1 minute. Return beef to pan, stir to warm and squeeze the juice from a fresh lime over the beef. Remove beef from pan immediately.
Serve beef with warmed tortillas, sour cream, grated cheese and lettuce.
Best beef cuts for stir-frying: Use beef stir-fry strips, or prepare your own from scotch scotch fillet, sirloin or rump.
Coat the meat in oil instead of adding oil to the pan or wok. You use less oil this way. You can also add ingredients like a little soy or grated ginger for flavour. Use your fingers to massage the oil into the meat strips.