Grab a skillet and warm it on medium heat. You will know it is ready when it starts to shimmer slightly. This step gets the onions and garlic nice and fragrant, making your kitchen smell great, so do not skip it.
Add the diced onions and minced garlic to the skillet. Stir occasionally until the onions turn translucent and soft. This takes a few minutes and helps to build a solid flavor base, but be careful not to let the garlic burn!
Toss in the chopped spinach and cook until it wilts down. You will see it change to a vibrant green, and that is when you know it is done. It adds a fresh taste and extra nutrients, but do not let it overcook as it will lose its texture.
Add the cream cheese, parmesan, and sun-dried tomatoes, mixing until everything melds together smoothly. This creates a creamy filling that packs a punch of flavor. Just watch for any chunks of cream cheese that might not melt well.
Pat the chicken breasts dry with a paper towel to help the filling stick. With a sharp knife, carve a pocket into each breast without cutting all the way through. This step is crucial, so take it slow to avoid any unnecessary rips.
Spoon your filling into each chicken pocket, pressing lightly to fit it all in. You will want the pockets to be nicely stuffed but avoid overfilling, which can cause the filling to leak out during cooking.
Lightly spray the chicken with your choice of cooking oil. You should see a nice sheen on the surface; this helps achieve that beautiful golden color during air frying. Do not drench it, or your chicken might not brown well.
Place the stuffed chicken breasts in the air fryer, ensuring they are not overcrowded. Cook until the chicken is golden and cooked through. Keep an eye on it because larger pieces may need extra time to fully cook.
After cooking, let the chicken rest for a few minutes before cutting into it. You will notice it retaining its moisture, which is key for juicy chicken. Skipping this step might leave you with drier meat, so be patient!