Soak the chickpeas in water overnight, then drain well. Place into a large pot and cover with fresh cold water. Add 6 cloves garlic, the whole celery stalks, carrot and onion. Bring to a boil and stir every 5 minutes until soft. Drain and let cool to room temperature. Discard the celery, carrot and onion, but keep the garlic.
Blend the remaining garlic, chopped celery, carrots, onions, parsley and cooked chickpeas in a food processor, in batches, making sure NOT to blend until completely smooth. Add the flour, olive oil, salt, basil, chili flakes, cumin, garlic powder, onion powder, oregano and eggs and mix well. Form into 1/3-pound patties or roll into balls. Refrigerate until ready to cook.
The veggie burgers are best when the mixture is made 1 day ahead.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.