4 potatoes, peeled and cubed
1 large onion, chopped
1 cup cider vinegar
5 cups milk
2 tablespoons butter, melted
In a medium saucepan, bring the potatoes, onion, vinegar and milk to a boil. Cover the pan, and simmer 15 minutes.
Meanwhile, prepare the potatoes and carrots according to package directions.
While the potatoes are cooking, mix the butter in small amounts and place them into the pan with the onions.
When the potatoes are done, stir them in butter mixture.
To serve, spoon 1/2 teaspoon of the butter mixture onto each potato and toss with 1/2 teaspoon of the onion mixture.