Bring the salted water to a boil and add the pasta. Cook stirring until your desired tenderness.
While pasta is boiling, heat a saute pan on high heat. Add the olive oil and sausage. Cook stirring until the sausage is cooked. Remove the sausage with a slotted spoon and in the same pan, add the onions and fennel. Cook for about 2 minutes or until softened. Add the roasted red peppers. Return the sausage to the pan and add the cooked, drained pasta. Stir in the Parmesan cheese and season to taste with salt and pepper.