Melt 1 Tablespoon butter and onion in a large skillet over medium heat. Cook onion until tender. Remove onion from pan and set aside.
Add 1 Tablespoon butter and olive oil to the pan. Add potatoes, seasoned salt, Italian seasoning and pepper. Cover and cook, stirring occasionally until slightly softened about 15 minutes.
Add sausage and cook about 10 minutes more. Stir in onions and peppers and cook until peppers are tender crisp.
Sprinkle with parmesan cheese if using.
Notes
If you prefer a more crisp sausage, cook the sausage in a separate skillet over medium high heat while the potatoes are cooking.