Add your butter and olive oil to a medium-sized sauce pan. Heat until the butter starts to foam, then add in the mushrooms and cook for 1-2 minutes.
Add in the garlic and balsamic vinegar, cook for a further 3-4 minutes. Add salt and pepper to taste and set aside.
While the mushroom sauce cooks, cook your boerewors on the BBQ or under the grill, for about 15 minutes, depending on the thickness, turning half way.
Remove form the heat and set aside to rest on a warmed serving plate.
Assemble your rolls with the boerewors and mushroom sauce, as well as shavings of parmesan if you like.
Reprinted with permission of Sarah Graham. To see
more recipes, click here.