In a 12 to 14 inch saute pan, heat olive oil until smoking. Add onion and cook until softened and starting to brown, about 6 to 7 minutes. Add grapes and cabbage and cook until cabbage is soft and some grapes have expanded, about 12 to 15 minutes.
Meanwhile, place sausage on grill and cook through, turning regularly, about 12 to 15 minutes. Add vinegar to cabbage mixture and season with salt and pepper. Place sausage over cabbage and serve from the pan.