Toss the potato wedges in 1 tablespoon oil, season to taste and bake in a preheated oven, 200°C (400°F), Gas Mark 6, for 30 minutes, turning after 15 minutes.
Meanwhile, in a large bowl mix together the mince with the red pepper, sweetcorn and onion. Season to taste and add the egg. Shape the mixture into 6 burgers and refrigerate until ready to cook.
Heat the remaining oil in a shallow frying pan over medium heat. Add the burgers, 3 at a time, and cook for 2 minutes on each side until brown. Transfer to a baking sheet and finish cooking in the oven, below the potato wedges, for 15 minutes or until cooked through.
Cut the rolls in half and cook them, cut side down, in the hot pan. Put a few salad leaves and tomato slices in each roll, add a burger and serve them with the sweet potato wedges.