Place the onions, butter, oil, sugar, and flour into a 4-quart slow cooker. Cook on high for 40 minutes. Add the stock and reduce to low. Cook for 8 hours

Cheese Toast:
Place 4 thin slices of Italian bread on a baking sheet. Sprinkle each with a teaspoon of shredded reduced-fat Italian mixed cheese or swiss cheese. Bake for 10 minutes at 350°F