Preheat oven to 400 degrees F and line a rimmed baking sheet with parchment paper (optional).
Add potatoes, pepper, beans, and onion to a large bowl.
Drizzle with oil and sprinkle with seasoning salt, Italian seasoning and garlic powder. Stir to coat.
Spread vegetables on baking sheet. Place Italian sausages on sheet pan, arranging vegetables so everything is in a single layer.
Bake at 400 degrees F for 20 minutes or until sausages and potatoes are cooked through (sausages should reach an internal temperature of 160 degrees F).