1. Saute onion in oil. Combine all ingredients, except frying oil. Let sit about 5 minutes for oats to soak up milk. If mixture seems stiff, add more milk. Taste mixture and adjust salt and seasonings.
2. Heat oil in frying pan and fry mixture by large spoonfuls. It may be necessary to flatten burgers in frying pan. Fry on both sides slowly allowing oats to cook. Use in burger buns or add gravy. These may also be baked at 350 degrees F for about 25 or 30 minutes on greased pan, turning half way. I prefer them fried.
3. If making gravy, saute onion and mushrooms in 1 tablespoon oil until soft and starting to caramelize. Push to one side of pan and add 2 tablespoons oil. When melted, add flour.
4. Stir the flour and oil together until blended and starting to brown. Turn down the heat if flour mixture starts to burn. Add water and bouillon cube. Stir everything together until mixture is boiling and thickened and bouillon is dissolved. Continue boiling for at least 2 minutes until flour is cooked. Taste and add salt and/or pepper if needed.