Preheat the air fryer: Set to 350°F (175°C) for a few minutes while you prep. A warm basket helps tortillas crisp evenly.
Shape the tortilla bowls: Lightly spray both sides of each tortilla with oil.
Press into an oven-safe ramekin, small metal bowl, or silicone mold that fits your air fryer. If you don’t have molds, crumple a sheet of foil into a ball and shape the tortilla around it to create a bowl.
Air fry the bowls: Cook 5–8 minutes at 350°F until golden and firm. Check at 4 minutes—edges go from pale to brown quickly.
If the center puffs, poke a small vent with a fork.
Cool and set: Carefully remove bowls and let them sit in the molds 2–3 minutes to set their shape. Transfer to a rack to stay crisp.
Cook the protein: In a skillet over medium-high heat, cook ground beef (or turkey/chicken) with a little oil. Break it up with a spatula until browned.
Add diced onion if using and cook until softened.
Season it right: Stir in taco seasoning, tomato paste, and water/broth. Simmer 2–3 minutes until saucy and well-coated. Taste and adjust salt or spice.
Keep warm on low.
Prep the fresh elements: Chop lettuce, halve tomatoes, slice onion, rinse beans, and dice avocado. Set out cheese, corn, salsa, yogurt, and lime wedges.
Assemble the bowls: Add a generous layer of lettuce to each tortilla bowl. Spoon warm taco meat over the top.
Add beans, corn, tomatoes, red onion, and cheese. Finish with avocado, a dollop of yogurt or sour cream, and salsa. Squeeze lime over everything.
Garnish and serve: Sprinkle with cilantro if you like.
Serve immediately while the bowls are still crisp.