The secret to great black bean burgers.

Green olives.  That's the secret.  Not lentils.  Not mushrooms.  Green olives.  This is how I make them.

Soak dry black beans in water for 8 hours or overnight.  Drain, rinse, and put in a large pot with enough water to cover them by about three inches.  Bring to a boil, reduce heat and simmer until tender.  Skim off the scum as it cooks, and after about 20 minutes add seasoning - salt, garlic powder, and oregano.  Lots.  Trust me.

Cook a bunch of brown rice.  I made a triple batch.  Be sure to salt your water.

Chop up a bunch of good green olives.

After the beans have cooked puree about 1/3 of them.  It doesn't need to be completely smooth.  Mix the puree with more beans, rice, olives and seasoning (salt if needed, onion or garlic powder) until they are holding together when you try to form a patty.

I use an ice cream scoop to portion them out and flatten them to about 1/2 to 3/4 of a inch thick on a baking sheet.  I refrigerate them or freeze them until ready to use.  Bake anywhere from 375 to 425 degrees, turning once so they crisp up on both sides.  No oil is needed, just use parchment paper or a silpat or something.  Or you can spray your pan with cooking spray.  They take about 20 to 30 minutes total.  We like them on sandwich thins rather than buns (way too much bread in a hamburger bun), with ketchup, mustard and pickles.  There must be pickles.