Heat olive oil in a sauté pan. When hot (but not smoking) add onions and garlic. Cook until tender and caramelized. Add a little salt.
Rinse rice and beans then add to the caramelized onions. Add bouillon, black pepper and approx. 3 cups of water to the pan (add enough water to cover rice and beans). Cook on high until water evaporates. Add another 3 cups of water (or enough to cover rice and beans) and continue to cook until rice and beans are well cooked—adding a little water at a time as needed. Mixture should be thick and water evaporated. Allow to cool.
When rice and bean mixture is cooled, add oat flour. Mix well until flour is incorporated into the mixture.
Form into 3-inch patties. Heat a little olive oil (or your favorite cooking oil) in a non-stick pan.
Add patties and cook on each side until brown. Serve warm.