Grease your pan with Butter (to taste). Lay the Potato (6) on the bottom to create one layer. Sprinkle some Grated Grated Parmesan Cheese (1/2 cup) and Shredded Cheese (2 cup). Season with Finely Ground Black Pepper (to taste), Salt (to taste) and Dried Oregano (to taste). Repeat layers until you've reached the top and used up all the sliced potatoes.
Fill the pressure cook with 1 1/2 cups of water and place the rack on the bottom. Place the pan with the potatoes on the rack. Pour the Whole Milk (2 cup) on the top of the potatoes.
Place the lid on the pressure cooker and set to bake for 25 minutes. Make sure the pressure valve of your pressure cooker is closed.
Meanwhile, preheat your oven to broil.
Once done, release the pressure of the cooker. Open the lid and remove the pan, sprinkle on some more cheese if desired, then set in the oven to broil for 8 minutes.
Once the top is nice and golden brown, remove and set aside to cool for 10 minutes before serving!