1.Boil, steam or microwave potato until tender; drain. Mash potato in large bowl with butter until smooth; spread over base of lightly oiled shallow 1.5-litre (6-cup) baking dish.
2.Preheat oven to moderate.
3.Combine remaining ingredients in medium bowl; pour over potato. Bake, uncovered, in moderate oven about 40 minutes or until top sets and is browned.
You can also use coliban or nicola potatoes for this recipe.Note