Scalloped Potatoes with Ham

2 medium onions, thinly sliced.
3 cloves garlic, minced.
6 tablespoons butter, divided.
4 tablespoons flour
3 cups milk
salt and pepper
4 russet potatoes, peeled and sliced:
- Peel these as needed. May not need all 4.
12 ounces 1/4 inch sliced baked ham
2 cups grated cheddar cheese (8 oz)

Preheat oven to 350 degrees. Lightly spray a baking dish.
In a skillet, cook onions and garlic in 2 tablespoons of melted butter until onions are golden brown. Season with salt and pepper and set aside.
In a saucepan, melt remaining 4 tablespoons of butter. Slowly whisk in flour and cook for one minute. Remove from heat and whisk in milk.
Return the saucepan to heat and bring to a simmer while stirring. Remove from heat once sauce begins to thicken. Season with salt and pepper.
Spread 1/3 of the white sauce in bottom of baking dish. Top with half the potatoes, onions, ham and cheese.
Spread another 1/3 of the white sauce, and top with remaining potatoes onions and ham.
Spread remaining white sauce, and top with remaining cheese.
Cover with sprayed foil to ensure cheese does not stick. Bake for 45 minutes.
If desired, uncover and bake until cheese is golden brown.