Onion Smashed Potatoes

1 envelope Lipton's Onion Soup Mix
6 potatoes, peeled and cut into 1-inch cubes
1/2 cup milk
1/2 cup butter

Cover potatoes in a saucepan with water and bring to a boil. Simmer about 20 minutes, or until tender; drain. Smash the potatoes. Stir in remaining ingredients.