Start with the onion & green pepper; in a saucepan, over medium heat, melt the butter and add the onions and sugar. Stirring constantly, cook the onions for 5 to 7 minutes until caramelised.
Add the green pepper and thyme, cider vinegar and white wine and continue to simmer for another 5 minutes or until the onions are softened and the liquid has evaporated.
Stir it occasionally to prevent anything from sticking to the base of the pan. Add a dash of extra wine if required.
Preheat the barbecue to medium or until the charcoal ashes turn white.
Place the sausages over indirect heat and cook for 8 minutes. Switch to a high heat for the last few minutes to help colour the sausages.
Once the sausages are cooked, warm the bread rolls and drizzle some mayonnaise or butter on the base. Add the salad leaves, the sausages and then your caramelized onion & green pepper