Pop the skewers in a dish or bowl of cold water and set aside to soak. This helps stop them catching and burning when the skewers are under the grill.
Peel and crush or grate the garlic. Finely grate the zest off the lemon. Pop them both in a bowl or dish. Add 1 tsp dried oregano, ½ tbsp sesame seeds and squeeze of juice from half the lemon. Add 2 tsp olive oil and a good pinch of salt and pepper. Stir to make a marinade. Add the beef stir-fry strips and turn to coat in the marinade. Set aside for 10 mins.
While the beef marinates, tip the bulgar wheat into a heatproof bowl and pour over 150ml boiling water. Add a pinch of salt and swirl a few times to mix, then cover with a plate and set aside to soak for 10-15 mins.
Peel the red onion and slice into around 8-10 wedges. Halve the pepper, scoop out the seeds and white membrane, and roughly chop the red pepper.
Line a baking tray or grill pan with foil and set a wire rack on it. Heat your grill to high.
Thread the beef, red onion and pepper onto the skewers and lay them on the wire rack. Scatter any leftover pepper or onion on the rack too. Grill for 8-10 mins, turning the skewers halfway through, till the beef and veg are lightly charred and the beef is cooked through.
While the skewers and veg grill, whisk together 1 tbsp lemon juice from the remaining lemon half, 2 tsp olive oil and a pinch of salt and pepper to make a dressing. Toss with the sweet salad leaves.
Drain any excess water off the bulgar wheat and arrange it on 2 plates with the salad leaves. Top with the beef skewers and any extra grilled veg. Scatter over the remaining ½ tbsp sesame seeds and serve.