Mashed Sweet Potatoes

1 1/2 sweet potatoes, peeled and quartered
2 tbsp Italian or balsamic vinaigrette dressing
1/2 cup onion, finely chopped
1/2 cup sour cream
1 tbsp brown sugar

Boil potatoes for 10 minutes or until tender. Drain and keep warm. Heat dressing in the same saucepan on med-high heat. Add onion and cook and stir for 5 minutes. Reduce heat to medium. Add potatoes and mash lightly. Add the rest of the ingredients and cook and stir until heated through. Serves 8.