Steak Sandwich with Tomato and Avocado Salsa

Ingredients

• 2 tablespoon olive oil
• 2 medium_piece brown onions (300g),sliced thinly
• 4 beef minute steaks (400g)
• 1 large avocado (320g)
• 2 medium_piece tomatoes (300g),seeded, chopped finely
• 1 tablespoon lime juice
• 1 tablespoon finely chopped fresh coriander
• 4 small pide, split horizontally
• 8 butter lettuce leaves