3 1/2 cups water
3 3/4 cups potatoes, peeled and cubed
1 medium onion, finely diced
2 teaspoons Dijon mustard
1 1/2 teaspoons salt
1 cup milk
1 teaspoon lemon juice
1 teaspoon prepared horseradish
1 teaspoon garlic powder
1 dash paprika
salt and pepper to taste
In a saucepan, combine water, potatoes, onion, mustard, salt, milk, lemon juice, horseradish, garlic powder and paprika. Mix thoroughly. Heat to boiling and reduce heat to low.
Heat oven to 350 degrees F (175 degrees C). Lightly coat a large skillet with nonstick spray. Pour 2 cups Greek yogurt mixture into one-third of the remaining pan amount. Press remainder over vegetables.
Bake at 350 degrees F (175 degrees C) for 50 minutes or until potatoes are just tender and set up.