Heat oven to 450 degrees F.
In a large bowl, toss together potatoes, peppers, onions, sausage and olive oil. Season with salt, Italian seasoning and red pepper. Evenly distribute between 2 rimmed baking sheets.
Bake at 450 degrees F. for 45 to 50 minutes or until vegetables are tender. Stir sausage and vegetables and rotate pans after 25 minutes.
Spoon sausage and pepper mixture into the Fill 'ems and serve.