Set A Deep Skillet Over Medium Heat And Coat With Cooking Spray. Add Sausages And Cook Until Browned. Remove From The Pan And Set Aside. Add The Onion To The Skillet; Cook And Stir Until Tender. Pour In The Tomato Soup And Bring To A Simmer. Return The Sausages To The Skillet And Simmer In The Soup For About 30 Minutes. Serve Over Mashed Potatoes.