In a large bowl, combine the cooked quinoa, broccoli, and beaten eggs. Add the breadcrumbs, cheddar cheese, green onions, garlic, salt, and pepper. Stir until the mixture is well combined and moistened.
Place the mixture in the refrigerator for 15 minutes. This will make it easier to form the fritters.
Form the mixture into fritters, pressing and flattening with your hands. The fritters should be about 3-inches wide and 3/4-inches thick.
You can bake, fry, or air-fry the fritters.
For Baking: Preheat the oven to 425 degrees F. Place a wire rack on a large baking sheet and spray with nonstick cooking spray. Place the fritters on the greased rack. Spray the tops of the fritters with nonstick cooking spray. Bake for 20 to 25 minutes or until fritters are golden brown and slightly crispy.
For Frying: In a large skillet, heat the olive oil over medium high heat. Fry the fritters for 5 minutes and then flip and cook for an additional 5 minutes or until the fritters are crispy. If you need to add additional olive oil while you are frying, you can. Place the fritters on a large plate that has been lined with paper towels and cover with aluminum foil while you finish cooking all of the fritters.
For Air-Frying: Spray the fritters with nonstick cooking spray. Transfer fritters to the air fryer, placing them in a single layer, making sure they are not touching. Cook at 400 degrees F until golden brown and cooked through, about 7 to 10 minutes. You might have to cook in batches, depending on the size of your air fryer.
Serve the broccoli cheddar quinoa fritters with marinara sauce, ranch, avocado ranch, plain Greek yogurt for dipping. You can also dip the fritters in tomato basil soup.