6 tbsp butter
1 small onion, finely chopped (1/3 cup)
2 cups heavy cream or half and half
1 tsp salt
1 tsp garlic powder
1 tsp onion powder
¼ tsp pepper
2 ½ to 2 ¾ cups milk
6 medium peeled potatoes, thinly sliced
2 cups shredded cheddar cheese (or more!)
Preheat oven to 350F. Grease 9×13″ dish.
Arrange sliced potatoes in prepared dish in one layer, slightly overlapping.
In a medium saucepan, melt 3 tbsp of the butter, add onion and sauté until tender. Slowly whisk in heavy cream. Stir in garlic powder, onion powder, salt and pepper. Heat until bubbling, about 5 minutes, and remove from heat.
Pour cream mixture over potatoes.
Sprinkle cheese over potatoes.
Cover and bake 1 hour. Uncover; bake 30 minutes until potatoes are tender. Let stand 5 to 10 minutes before serving.