In a skillet over medium heat, cook the ground beef until browned. Add diced onion (if using) and cook until softened. Stir in taco seasoning, water, and tomato paste (if using). Simmer for 3–5 minutes until thickened.
Lay out your tortillas. Spread about 2 tablespoons of refried beans on one half, then add 1/4 cup taco beef and a generous sprinkle of shredded cheese. Fold the tortilla in half to create a taco and press down.
Preheat air fryer to 375°F. Lightly spray tacos with oil (optional for extra crispiness). Place in a single layer and cook for 6–8 minutes, flipping halfway, until golden and crispy. Option to sprinkle a little cheese on top. Read blog post for oven/stove top instructions.
Once cooked, open slightly and fill with shredded lettuce, salsa, and a spoonful of Greek yogurt.
Serve immediately.
Store leftover tacos in an air tight container for up to 4 days.
Notes
If you're hosting a big group I suggest baking them in the oven because you do them all at once vs having to batch air fry them.
You can make these for mealprep and reheat them and then fill with your favorite toppings or just bring some salsa to dip.