Stir chili sauce and sour cream in small bowl. Chop 1 sausage; slice remaining sausages 1/2 inch thick.
Heat oil in nonstick skillet over medium heat. Add mushrooms and chopped chicken sausage; cook for 2 minutes. Stir in potatoes, green onion, Italian seasoning and pepper. Cook, covered, stirring occasionally, until the potatoes are tender, 8 to 10 minutes. Add sliced sausages; cook, covered for 3 minutes. Serve with chili sauce. Makes 4 servings.