Preheat the oven to 425 and line a rimmed baking tray with unbleached parchment or a silpat mat.
In a small bowl, whisk together the flax and water and set aside to "gel"
Place 1 cup of beans, brown rice, red peppers and ½ the cilantro in a large bowl, set aside.
Place remaining 2 cups of beans, remaining cilantro, oats and all remaining ingredients (except for oil) into bowl of food processor and pulse until a chunky paste forms. Be careful not to over process and wind up with mush.
Add the bean puree and flax mixture to the large bowl of other ingredients, and mix well.
You are now ready to form this mixture into "burgers" but must first decide if you're making full size burgers (you should get about 6) or mini sliders (12 mini burgers). Also, decide if you're making these and cooking them NOW (method A)....or forming into a log to refrigerate or freeze for "slice and bake" burgers later (method B).
METHOD A: Use a large scoop to portion out burgers onto prepared pan. Use your hands that have been moistened with water to do the final shaping. METHOD B: Scoop burger mixture onto the middle of a large piece of unbleached parchment paper and roll into a large log---diameter the size you ultimately want your burgers to be. Roll the ends (it will resemble a large tootsie roll). Place in the fridge for up to 5 days or the freezer for up to 3 months. When ready to use, slice and "bake" as directed below.
Place baking tray in preheated 450 degree oven. Bake for 15 minutes. Flip, and bake for another 10-15 minutes until burgers are firm.
FOR THE RED PEPPER SAUCE:
Place all ingredients in a blender or food processor and blend until smooth. Sauce will stay good iIn fridge for a week.
Notes
SUBSTITUTIONS: If you don't care for cilantro (I know some people think it tastes like soap), substitute fresh parsley. If you don't have black beans, sub for any bean you do have. Any grain can take the place of brown rice. If you don't eat oats, use almond flour.