Thinly slice the potatoes and cut the ham into small squares. In a medium bowl whisk together the heavy cream, milk, garlic, flour, salt, black pepper and cilantro. Spray a round pan that can easily fit inside your pressure cooker (I used 8" round with 2" high sides) with non stick spray. Layer half of the potatoes and ham in the round pan, followed by half of the cheese. Pour half of the liquid over the top. Repeat with the rest of the potatoes, ham and liquid, reserving the remaining cheese for later. Pour 1 1/2 cups of water into the liner of your pressure cooker and place the round pan on top of your trivet. Carefully lower your pan down into the liner of your pressure cooker. Close the lid and ensure the pressure release valve is closed as well. Cook on HIGH pressure for 25 minutes, followed by a QUICK RELEASE of the pressure. Carefully pull the pan out by the trivet handles and place pan on a baking sheet. Top with the remaining cheese and place under the broiler in your oven for 3 minutes. (Or if you don't want to turn on your oven you can just leave the potatoes in the pressure cooker, top with cheese and cover for 5 minutes before removing from liner). Let the potatoes sit for about 5 minutes before serving. Enjoy!