In a large saute` pan over a medium-high heat add 1 tablespoon of the oil. Using a fork prick the sausage links all over. Place the links in the saute pan and cook until lightly browned on all sides, about 5-6 minutes. Transfer to a plate and let cool for a few minutes then slice the links in half. Set aside.
Preheat the oven to 450 degrees.
In a large mixing bowl toss together the rest of the oil, sliced potatoes, peppers, mushrooms, onions and garlic. Season with salt and pepper to taste
Spread the mixture in a large roasting pan or large baking sheet. Top with the sausage and roast for 30-40 minutes turning halfway though.