Creating Baked Ham and Scalloped Potatoes is simple. Follow these easy steps to achieve a delicious dish:

1. Preheat the Oven: Preheat your oven to 350°F (175°C).
2. Prepare Baking Dish: Grease a 9×13-inch baking dish with butter to prevent sticking.
3. Layer Potatoes: Place half of the sliced potatoes in the bottom of the baking dish.
4. Add Ham: Layer half of the diced ham over the potatoes.
5. Onion Layer: Sprinkle half of the chopped onion over the ham layer.
6. Seasoning: Sprinkle a pinch of salt, pepper, and garlic powder over the layers.
7. Cheese Layer: Add half of the shredded cheddar cheese on top.
8. Repeat Layers: Repeat steps 3 to 7 with the remaining ingredients, finishing with cheese on top.
9. Prepare Cream Mixture: In a saucepan, melt the butter over medium heat. Stir in flour and cook for 1 minute.
10. Add Cream and Milk: Gradually whisk in the heavy cream and milk until smooth and slightly thickened.
11. Pour Cream Mixture: Pour the cream mixture evenly over the layered potatoes and ham.
12. Cover with Foil: Cover the baking dish with aluminum foil to prevent over-browning.
13. Bake: Bake in the preheated oven for 45 minutes.
14. Remove Foil: After 45 minutes, remove the foil and bake for an additional 15-20 minutes until the top is golden and bubbly.
15. Cool Slightly: Allow the dish to cool for a few minutes before serving.

These steps will guide you in preparing a truly incredible Baked Ham and Scalloped Potatoes that will surely impress your family and guests.