Toast your walnuts in a pan until they release their oils and start to become fragrant, just a couple of mins.
To the bowl of a food processor, add roasted peppers, shallot, egg, chili powder, garlic powder, paprika, salt and pepper. Blend until a paste forms.
To a bowl, add the black beans and mash with a fork. Leaving some beans in tact. Add in the puree you made along with brown rice. Mix well. If the mixture seems too wet add up to 1/4 cup of breadcrumbs. Mix well and refrigerate for 30 mins to tighten up.
Form you patties. With the flame in medium. Add a neutral oil of your choice to a fry pan. Add the burgers to the hot oil and cook on both sides under golden and dried out a bit. This can take up to 4 mins on each side. These burgers can be grilled as well, just make sure you grease the grill well or they will stick!
You can add cheese on top at the end of the cooking time if you like.