Bring 2 cups water to boil and add quinoa. Cook it about 10 minutes or until tender. Discard any remaining liquid and set aside to cool down.
In a large bowl, mix well together onion, garlic, corn, black beans, spinach. Add cooled quinoa and all the spices, barbecue sauce, and tomato sauce. Taste it and add salt and pepper accordingly to your taste.
Add cornstarch and mix it well with your hands. The mixture should be now sticky enough to hold together. With your wet hands, divide mixture into 4 pieces and make patties.
In a frying pan, heat a little bit of olive oil on a medium to low heat. Place patties in the pan and fry them for 5 minutes on each side or until slightly golden brown. Add more oil if necessary. Cook the patties in two batches if your frying pan is not big enough.
Make your burgers by adding ingredients in layers. Serve with chipotle sauce and/or fries.
Enjoy!