Wash, peel and slice the potatoes. Slice the potatoes somewhere in between 1/8 and 1/4 of an inch thick.
Add the chicken broth, onion and garlic powder, into the Instant Pot.
Place the sliced potatoes and cut ham into a steamer basket and place in the Instant Pot.
Cook on Manual HIGH for 0 minutes. Quick release the pressure.
Remove the potatoes and ham, set aside.
Turn the Instant Pot onto Saute Normal (or the middle setting).
In a small bowl, combine the butter and flour to create a paste.Add the paste to the chicken broth in the Instant Pot. Stir until the broth has thickened.
Add the milk to the Instant Pot, whisking to combine. Whisk occasionally until the sauce has thickened. This should take about 5- 10 minutes. Season liberally with salt and pepper. Taste and adjust seasonings as needed.
Pour 1/3 of the sauce into the bottom of your baking dish. Pour 1/2 of your cooked potatoes and ham on top of the sauce. Repeat again with 1/3 of the sauce, the remaining potatoes and ham topping the last layer of potatoes and ham with the remaining sauce.
Sprinkle the cheese on top, if desired. Broil on the middle rack until the sauce is bubbling and the top is golden brown.
Best if the potatoes cool for about 10 minutes before serving.
Garnish with parsley, if desired.
*Instructions for making this without an Instant Pot is in the body of the post.