Ground beef is simmered with onions and baked with potatoes in a rich silky combination of sour cream and half and half, topped with mozzarella cheese.
Step 1: Preheat oven to 375 degrees.
Step 2: Brown ground beef with onion in a large pan until the onion has softened and there is no more pink left in the meat. Drain the hamburger meat and set aside.
Step 3: In the same pan, melt the butter over medium heat. Add flour and combine into a paste. Cook constantly stirring for one minute.
Step 4: Add the half and half and beef broth. Whisk together and simmer until the sauce thickens for about 5-7 minutes.
Add the salt, black pepper, onion power and garlic powder and incorporate into the sauce.
Step 6: Slice the potatoes into thin slices about ¼". You can peel the potatoes or leave the potato skin on. A mandolin is a great tool to use to speed up the process.
Step 7: In a prepared 9 x 13 pan layer half of the potatoes in the bottom of the pan. Pour half of the sauce over the potatoes and sprinkle half of the cheese over the sauce. Repeat with the rest of the potatoes, meat mixture and cheese.
Step 8: Bake covered for 1 hour. Remove cover and bake for an additional 15 minutes until the cheese begins to brown. Let the casserole rest for 10 minutes before serving.