Heat oven to 425°F.
Coat the bottom of a large roasting pan with the olive oil. Add the sausage pieces and roast at 425°F for 15 minutes.
Stir in the potatoes, peppers, onion and garlic. Toss with the salad dressing. Roast for an additional 40 minutes or until potatoes are fork tender. Stir twice during cooking.
Serve with tossed salad and crusty bread if desired.