For the stir-fry:

• 500g (1 lb) beef sirloin or rump steak, cut into strips
• 1 large red onion, cut into thick slices
• 2 tomatoes, cut into wedges
• 1 yellow chili pepper (aji amarillo), sliced
• 2 cloves garlic, minced
• 2 tbsp soy sauce
• 1 tbsp red wine vinegar or white vinegar
• 1 tbsp oyster sauce (optional)
• Salt & black pepper to taste
• Fresh cilantro, chopped
• 2 tbsp vegetable oil

For serving:

• Cooked white rice
• French fries (homemade or frozen)