Measure 12 cups water into a heavy pot. Add black beans and rice. cover, bring to boil over high heat. After water reaches a boil (~ 5 minutes) reduce heat to medium and cook at medium boil for 1 hour, or till beans are tender. (The time it takes depends on the age and dryness of the beans)
when the beans are tender, drain into colander, turn into bowl.
Mash beans (not totally smooth, leave some beans unmashed)
Add remaining ingredients, taste for seasonings.
Center the oven rack, Preheat to 425°F. Line baking sheet with parchnemt paper and spray with olive oil spray. (You can also just spray the baking sheet, if you don't have parchment paper).
Using a half cup to measure, pack some of the bean mixture and tapi it out into one hand. using your free hand, press lightly to form burger (~4 inches in diameter)
Carefully place burger onto baking sheet. Continue forming and placing burgers, leaving a little space to make flipping them easier.
Spray tops of burgers lightly with olive oil spray.
Bake the burgers in oven for about 25 - 30 minutes until tops are just firm to the touch.
Using two spatulas, carefully turn the burgers, spray the tops with olive oil spray.
Bake for about 30 minutes more, until just firm to the touch.
Remove from the oven and allow to cool and firm up (~10 minutes)
These burgers freeze well. To thaw, cook in preheated 400°F oven for ~5 minutes or until heated through.
These burgers are fragile, handle with care.