In a large skillet over medium heat, add the ground beef and chopped onion, cooking for 7-10 minutes until browned and no pink remains. Drain any excess fat and transfer the mixture to a bowl.

Wash and thinly slice your potatoes to about 1/8 inch thick. Arrange them on a clean cutting board.

In the crockpot, start layering half of the sliced potatoes at the bottom, followed by half of the beef mixture, and a portion of cheese. Repeat layering, finishing with cheese on top.

In a mixing bowl, whisk together the cream of mushroom soup, milk, garlic powder, salt, and pepper until smooth. Pour the sauce over the layered ingredients in the crockpot.

Cover the crockpot and set to cook on low for 6-8 hours until the potatoes are tender and the cheese is bubbling.

In the last 15 minutes of cooking, sprinkle the remaining cheddar cheese on top and garnish with fresh herbs if desired.