Heat oil in a heavy-based frying pan. Add beef slices and onion and fry lightly for a few minutes.
Add lemon juice, Spur Peri-Peri Sauce, Spur Seasoning Salt and pepper. Simmer for a few minutes. If needed, thicken sauce with a paste of 15 ml (1 Tbsp) flour and a little water.
Serve beef slices with sauce on Portuguese rolls or any other bread rolls of choice.