Slice the onion into wedges; the jalapeno in half and remove seeds, and add both a food processor. Pulse a few times to roughly chop.
Add cooked sweet potato and the black beans, reserving ⅓ cup beans. Process until mostly smooth.
Add remaining ingredients, including reserved beans, to a medium mixing bowl. Add processed potato mixture to bowl and stir to combine.
Place the bowl of burger ingredients in the fridge to chill for 20 minutes. During this time, preheat the oven to 400 F if baking, and line a baking sheet with parchment paper.
Once chilled, divide the mixture into 6-8 “patties" and place on the prepared baking sheet. Bake for 10 minutes each side, spraying with oil if desired. If not baking, burgers may also be pan-fried for 3-5 minutes on each side in a good non-stick pan, using non-stick cooking spray or a touch of oil to cook, if needed.
Serve on a bun with your favourite burger toppings such as mustard, ketchup, onion, lettuce and tomato.