Step 1 BBQ the sausages until golden brown, turning once. Remove from BBQ and set aside. Or if not using the BBQ fry the sausages in a little oil in a heavy based pan for 20 mins, then set aside.

Step 2 Heat a pan over a low heat and cook the onions in the olive oil until lightly browned and soft for 3-5 mins. Add the balsamic vinegar and sugar and cook for 1 minute. Add the garlic and sliced peppers and cook for another 5-7 minutes, or until softened. Season to taste.

Step 3 Slice each roll down the centre and spread one half with ½ tsp mustard. Sprinkle the grated cheese on both the cut sides of each roll. Place under a preheated grill (or on a lidded BBQ) for a few minutes just to slightly toast roll and melt the cheese.

Step 4 Fill each roll with a sausage and a dollop of the onion mixture.