In a food processor, combine the kidney beans, garlic, tomato paste, vinegar, and mustard. Pulse until pureed. Add the green onions, parsley, oregano, salt, and pepper to taste, and process to break up and blend. Add the oats and pulse to begin to incorporate. Transfer the mixture to a large bowl (or remove the blade) and stir in the olives and red pepper (if using; see note). Refrigerate the mixture for 30 to 45 minutes, then shape into patties with your hands (see note). To cook, wipe a smidgen of oil over a non-stick skillet on medium/medium-high heat. Cook the patties for 6 to 8 minutes per side, or until golden brown. Alternatively, bake the patties for about 15-20 minutes at 400 degrees, flipping once through cooking. Makes 6-7 patties.