My friend Holly has a roller/flaker, and has convinced me that I needed one also. Yes, she was right on! Now I'm going to convince you that you need one, too! This is a flaker made by an Italian company, called the Marga. I paid $89 for mine at a local food storage store (they sell dehydrated foods in #10 cans, grains, appliances, etc).
You put the groats (oat grain) in the hopper, set it on 3 (to flake) and turn the handle. In 30 seconds or less, you have freshly flaked oats. The picture below is of groats in the hopper.
I ran some back through on setting 1 to make instant oatmeal just so you can see. When groats are processed, the finer the grind, the quicker it cooks. Above would be the 5 minute cooking oats (which is my preference) and below would be the quick cooking oats, which would take 1-2 minutes to cook. If you process it further, it would be instant.
When you cook any grain, you use one part grain to 2 parts of water. So, for 1/2 c. flaked oats I used 1 c. water. If you like it thinner, just add a little more water, or add milk when you serve it.
Hopefully this has given you a little more knowledge about oats. Steel cut oats are groats that have actually been cut with steel blades. It is really delicious, too, you just can't do it at home. For the family that wants to store grains for their 1 year supply of food, groats and a roller/flaker is really a great idea. The nutritional value in the grain is preserved by waiting to process it just before using it. By the way, you can flake wheat, barley, etc. with the Marga.