I got this recipe off a Weight Watcher's message board:

1 can black beans
1 cup cooked brown rice
1/2 green pepper
1/4 c. chopped onion
1/4 tsp. cumin
1 tsp. chili powder

Mash beans. Add other ingredients. Mix well. Spoon into non-stick skillet with oil. (They do not hold together well.) Brown on each side. Serve on a bun with salsa.

I modify this-use dry beans, cook my rice in more than water, etc. Only one time did I actually get a facsimile of a burger. More often than not, I make it like a hash. Either way, the salsa makes it tasty and it is not too shabby on fiber.