I have recently switched to a black granite ware to cook oatmeal. Black granite is great because it is made of low-carbon steel with a glass coating, and so there is no chemical added to the surface; it also cooks fast and evenly.
Given the granite ware requires at least an inch of liquid to cover whatever you are cooking, I have been cooking my oatmeal for one person with over an inch of water/almond milk everyday. You guess it right that the oatmeal is swimming in a mushy soup. Then I visited my sister, and she kindly cooked me a hot oatmeal everyday – creamy but still chewy with no excess liquid.
A light bulb! I have been cooking not with the right ratio of liquid to the oatmeal but with the right amount of water to the pot!
To cook a nice hot oatmeal: pour in 1 cup of rolled oats and then a bit more than 1 cup of liquid to just cover the oats (water + milk you prefer). Heat them together in medium heat. Add a pinch of salt (in my case, I add some cumin) and some chia seeds. Then stir minimally and let the oat simmer in the liquid until the liquid has been absorbed. After the oatmeal is cooked, I add blueberries, walnut, and a teaspoon of flax oil. A satisfying meal with a perfect taste!
Lesson learned: you cook to make the food taste good and not to protect your cookware; or, when you do something, do not first focus on whether you will look good, but whether you are doing the appropriate thing.