To make oatmeal in a microwave using quick-cooking oats, put 1/2 cup quick-cooking oats, 1 cup water and a dash of salt into a medium microwave-safe bowl. Microwave on the highest power for 1 1/2 to two minutes, then stir.
Use the same process when starting with rolled, or old-fashioned, oats, but microwave for 2 1/2 to three minutes. For steel-cut oats, use 2 cups of water for 1/2 cup of steel cut oats. Put the ingredients into a 2-quart microwaveable dish and cover. Cook on high for five minutes. Stir, then cook uncovered for an additional five minutes.
Different varieties of oats go through separate processes to ready them for consumption. Rolled oats are steamed and rolled into thick flakes. When prepared on a stovetop, these oats typically take at least five minutes to cook. Quick-cooking oats are steamed and rolled much thinner. On the stovetop, they are done in about one minute.
Steel-cut oats are also known as Irish, Scotch or pinhead oats. They are cut before being steamed, but they are not rolled, which makes them much thicker and chewier than rolled or quick-cooking oats. They take about 25 minutes to prepare on a stovetop.