Pour about 1 inch of water into a skillet or wok and bring to a boil over medium-high heat. Place the cauliflower in a steamer basket (or use a sieve) and set it over the boiling water; steam until tender, about 4–8 minutes. Remove and let cool until you can handle it.
Coarsely chop the cooled cauliflower so it mixes well but still has some texture.
Bake the cod at 400°F (200°C) for 20 minutes until cooked through. Let it cool slightly, then flake the fish with two forks.
In a large bowl, combine the flaked cod, chopped cauliflower, cooked quinoa, minced garlic, mixed eggs, nutritional yeast, sliced green onions, lemon juice, salt, pepper, and almond flour. Mix thoroughly by hand; adjust texture with an extra half egg if too dry or add more breadcrumbs/quinoa if too sticky.
Form the mixture into patties by hand. Prepare three shallow bowls with almond flour (or chosen flour), egg whites, and breadcrumbs. Dredge each patty in flour, dip in egg whites, then coat with breadcrumbs. Place the coated patties on a tray. Chill in the refrigerator for 1–24 hours if time allows to help them hold their shape.
Preheat the air fryer to 400°F (200°C). Arrange the patties in a single layer in the basket (do not overcrowd). Air-fry for 10 minutes, flip, then cook for an additional 5 minutes until golden and crisp.