Begin by slicing the chicken breasts horizontally to create thin fillets, ensuring even cooking. This helps the chicken cook through in just 4-5 minutes. Pat the slices dry with paper towels for a crispier finish.

In three separate bowls, create a coating station: mix all-purpose flour with salt, black pepper, garlic powder, onion powder, paprika, and cayenne in one bowl. In another, whisk the egg with a splash of water. Finally, place the breadcrumbs in the third bowl, ready for coating the chicken.

Take each chicken fillet and coat it first in the seasoned flour, shaking off the excess, then dip into the egg mixture. Finally, thoroughly coat each piece with breadcrumbs, ensuring a generous layer for that perfect crispy texture.

In a large skillet, pour in enough vegetable oil to cover the bottom completely and heat it over medium-high heat. Monitor the oil until it shimmers, indicating it’s ready for frying.

Carefully add the coated chicken fillets to the hot oil without crowding the pan. Fry each piece for about 4-5 minutes on one side until golden brown, then flip and cook for another 4-5 minutes.

As the chicken cooks, slice the hamburger buns in half and lightly toast them in a separate pan or toaster until golden brown.

In a small bowl, combine mayonnaise, Dijon mustard, lemon juice, and lemon zest. Stir until smooth.

Spread a generous layer of the sauce on the bottom half of each toasted bun. Place one crispy chicken fillet on top, followed by fresh lettuce and tomato slices. Add parsley for garnish and crown with the top half of the bun.

Serve immediately while hot.