Steel-cut oats, sometimes called Irish oats, come from the inner part of the oat kernel and are considered a whole grain. While you can certainly prepare steel-cut oats on the stovetop, the process is simpler when you prepare them in a rice cooker. And, you'll get a creamier consistency. Don't be afraid to make a large quantity at once -- unlike rolled oats, steel-cut oats store well and reheat without turning into a gooey mess.
Measure out the desired quantity of steel-cut oats with a measuring cup. Steel-cut oats expand to four times their dry size, so 1 cup of dry oats makes up to 4 cups of cooked oats.
Pour the steel-cut oats into a fine-mesh strainer and rinse the oats under cool water.
Pour the oats into the bottom of the rice cooker's container. Add water using a ratio of 3 to 4 cups water for every 1 cup of steel-cut oats. Measure the water, rather than estimating.
Turn on your rice cooker. If you have a specialty setting for brown rice or porridge, use that setting instead of the general or white rice one. Let the rice cooker cook as if you were making brown rice. Depending on the quantity you're cooking, it could take 60 to 90 minutes to cook.
Add water or milk to thin out the oatmeal if it's too thick. Add additional flavorings such as brown sugar, white granulated sugar, raisins, cinnamon or maple syrup once it is in a bowl and ready to serve.