Oat flour is made by grounding uncooked oats (rolled oats, Scottish porridge oats) until flour like consistency.
This can be easily done using a blender. A high-speed blender is not necessary for this. Any good blender will be able to blend/ground the oats into oat flour. And it doesn’t take long. Only few 1-2 minutes of blending is needed.
Good idea is to ground bigger batches and store oat flour in an airtight container for whenever you need it.
As an alternative to making your own, oat flour can be bought right now. You don’t have to ground it yourself if you don’t want to so to make things easier you can just buy it.
Oats are gluten free but since they are processed in non-gluten free facilities there are very likely contaminated with gluten. To be sure oats are gluten free you need to buy gluten free variety to make your own oat flour or buy gluten-free oat flour.
Oat flour can be used for so many dishes. Pancakes, waffles, muffins can be made with using just oat flour or as a blend of oat flour with a different flour. You can use oat flour to make porridge for extra creamy consistency or in your smoothies as a carb/protein boost.