From The Common Grill Cookbook
4 sweet potatoes, peeled, cut in 1" pieces
1 Granny Smith apple, peeled, cored, and diced fine
1/2 c heavy cream
1/4 c butter
2 teaspoon brown sugar
1 tablespoon maple syrup
1 teaspoon kosher salt
1/2 teaspoon black pepper
Put sweet potatoes in a large pot, cover with water and bring to a boil. Cook until tender.
In a saucepan combine apple, cream, butter, brown sugar, and maple syrup. Bring to a simmer.
Drain potatoes and transfer to mixer and whip with wisk. Gradually add cream mixture and whip. Add salt and pepper.