Make sure beans and potato are cooked. I cooked the potato in the microwave but the oven would work too. Just don’t boil because that brings in too much moisture.
Put all ingredients (except 1/4 cup salsa) into a blender and puree until smooth. Add in the extra 1/4 cup and pulse in for a chunky addition.
Add beans, potato, salsa, and cornmeal/brown rice flour and pulse again until chunky. You don’t want this too pureed or it will turn into a dip.
Put mixture into the fridge for at least 20 minutes, an hour is best. Making this the night before and letting it sit is even better. This helps all flavors marinate and combine into a more flavorful burger.
Once mixture is ready, shape into 4 patties. Using an indoor or outdoor grill on medium high, grill on each side for 20 minutes. You can also bake these on parchment lined cookie sheet on 375°F (190°C) for 15-20 minutes on each side.