Prep the air fryer. Preheat to 390°F (200°C) for 3–5 minutes. A hot basket helps the patties crisp up.

Drain the tuna well. Press out excess liquid using the can lid or a sieve. Dry tuna = better texture and no soggy burgers.

Mix the base. In a bowl, combine tuna, breadcrumbs, egg, mayo, Dijon, onion, celery, parsley, lemon zest and juice, garlic powder, salt, and pepper. Use a fork to break up the tuna, then switch to your hands to bring the mixture together.

Adjust the moisture. The mixture should be moist but hold its shape. If it crumbles, add 1–2 teaspoons mayo or a splash of lemon. If it’s too wet, add 1–2 tablespoons breadcrumbs.

Form patties. Shape into 4 equal patties, about 1/2 to 3/4 inch thick. Press the edges so they’re compact and smooth.

Oil the surface. Lightly spray both sides of each patty and the air fryer basket. This helps browning and prevents sticking.

Cook. Air fry at 390°F (200°C) for 8–10 minutes, flipping at the 5-minute mark. They’re done when golden brown and firm to the touch.

Toast buns (optional). Pop buns into the air fryer for the last 2 minutes. Warm, slightly crisp buns make a big difference.

Build and serve. Add your favorite sauce, greens, and toppings. Serve hot and enjoy the crunch.