These vegetarian burgers pack a ton of flavor and come together quickly once the rice has cooked. I highly recommend using the toppings for the most messy and delicious results! See the other recipe card in this post for details on how to cook these burgers in a skillet.
Preheat the oven to 450 degrees.
In a small bowl or cup, mix the ground flaxseed with 3 Tbsp warm water. Set aside for 10 minutes to thicken.
Add the black beans to a mixing bowl and pat dry with a paper towel. Use a fork or wooden spoon to smash the beans (Note: they don't need to be fully smashed, maybe 60/40 smashed versus not. See the pic of the mixing bowl in my post.)
For the corn, I use frozen corn and run hot water over it in a colander. Then I wrap a paper towel around it and squeeze the water out. Add the corn to the bowl with the beans.
Add brown rice, salsa, cilantro, spices, salt, and thickened flaxseed mixture, and stir to combine.
Form into patties and place on a baking sheet sprayed with cooking spray. Bake at 450 for 20 - 25 minutes. (Using my oven, they are ready to flip after 23 minutes.) Using a spatula, carefully flip the burgers (re-shaping slightly with the spatula if needed) and continue to cook for another 5 - 8 minutes. If you are using cheese, I add it in the last minute of cooking to allow it to melt on the burgers.
To make the sauce, mix the sour cream and adobo sauce together in a small bowl. Adjusting the amount of adobo sauce will control how spicy this ends up. Once done, add the burgers to a bun and top with lettuce, tomato, avocado, and sauce!
Regarding the salsa: I usually use homemade salsa for this, because we typically have a batch in the fridge, but if I don’t, I just use a can of Rotel tomatoes + cilantro processed in the blender until it’s not chunky. You can definitely use your favorite store bought salsa, however, I recommend pureeing it in the blender or food processor to avoid chunks in the burgers.