In a food processor, blend black beans and kidney beans to a fine mash. It is alright if some bean chunks still remain solid.
In a large mixing bowl, add to bean mash any desired spices. I strongly reccomend liberal amounts of chili powder, cumin, onion powder, and garlic powder. You might also add an adobo seasoning.
Should you desire, you might add any kind of chopped or shredded vegetables at this point. From experience, I find salsa is a nice addition.
Mix in 1.5 cups of cooked brown rice into bean mash and stir till even consistancy. Gradually fold in entire package bread crumbs- bean mash will visibly thicken, it is advisable to use your hands at this point.
Grab small palmfulls of bean mix and flatten into burger sized patties. I generally find I make about 28 patties in one go- this is variable as yours may be smaller or larger.
I freeze patties for weeks (months) at a time in an air-tight container or freezer bag.
To cook- either bake in a toaster oven until exterior is crusty and crispy, or pan fry with a small amount of oil or cooking spray. These are very firm burgers and will hold up extremly well- better than any other bean burger ive seen!
Dress your burgers with any number or great things- BBQ suace is a particular favorite.
Also try crumbling cooked burgers and using the 'meat' as taco filling- tastes delicious especially with taco sauce.