Method

1. Preheat a barbecue plate to medium. Put oil and onion in a small bowl and toss to coat. Transfer onion to the barbecue plate and reduce heat to low. Cook, stirring occasionally, for 25-30 minutes or until onion is very tender. Transfer to a plate.

2. Meanwhile, preheat a barbecue grill to medium-high. Spray each side of the steaks with the cooking spray. Season with pepper. Place the steaks on the barbecue grill and cook for 1 minute on each side, for medium, or until cooked to your liking. Transfer to a large plate. Cover loosely with foil and set aside for 2-3 minutes to rest.

3. Slice each piece of Turkish bread in half through the centre. Spread the cut side of each base with spicy tomato sauce. Top each with lettuce, tomato, cucumber, beetroot, steak and onion. Top each with a remaining half of bread.

4. Cut each into 4 pieces to make 8 steak sandwiches, then serve.

Tips:
- Up to 1 day ahead: Slice the steak and put in a resealable plastic bag. Keep in the fridge.
- In the morning: Combine the oil and the onion and put in an airtight container. Keep in the fridge.
- In the morning: Slice the bread and return to the original bag.
- In the morning: Put the tomato sauce, shredded lettuce, tomato slices, beetroot and cucumber ribbons in separate airtight containers. Keep in the fridge.