This looks really good! I found it on the
 French's recipe website along with 170 more:
 
 
3 cups prepared hot mashed potatoes 
1 cup sour cream 
1/4 cup milk 
1/4 tsp. garlic powder 
1 1/3 cups (2.8 oz.) FRENCH'S® Original or Cheddar French Fried Onions 
1 cup shredded Cheddar cheese 
Directions:
 
MIX mashed potatoes, sour cream, milk and garlic powder.
SPOON half the mixture into 2-qt. casserole. Sprinkle with 2/3 cup French Fried Onions and 1/2 cup cheese. Top with remaining potato mixture.
BAKE at 350°F for 30 min. or until hot. Top with remaining 2/3 cup onions and 1/2 cup cheese. Bake 5 min. or until onions are golden.