Using a food processor helps these burgers hold their shape without the use of a binder like beaten egg. However, you can make these without a food processor by mashing the beans well, adding the other ingredients, and kneading the mixture with your hands until it holds together. The patties will be a little more fragile, so handle them with care.

Heat in a medium skillet over medium heat:

Add and cook, stirring, until browned, about 8 minutes:

Stir in and cook until fragrant, about 1 minute more:

Scrape the onion mixture into a food processor. Add:

Pulse, scraping down the sides of the bowl several times, until the mixture is finely ground and holds together when squeezed (if there are some whole beans or grains of rice that is fine). Shape into 4 patties. Heat in a large skillet (preferably nonstick) over medium heat:

Place the burgers in the skillet and cook, flipping once, until well browned on both sides, about 5 minutes per side. You may need to add more oil to the skillet to brown the second side. Serve on:

With: