Step 1: Prep the chicken
Place the chicken breasts on a cutting board and carefully slice them horizontally to create thinner pieces. This not only speeds up cooking but also gives you more surface area for that irresistible crispy coating.

Step 2: Marinate in buttermilk
Place the chicken pieces in a bowl or zip-top bag and pour the buttermilk over them. Let them sit for at least 20–30 minutes (or up to a few hours in the fridge). The buttermilk tenderizes the chicken and adds flavor.

Step 3: Season and set up your dredging station
In a shallow bowl, combine the flour with salt, black pepper, garlic powder, onion powder, paprika, and a pinch of cayenne. In another bowl, whisk the egg and water until smooth. Place breadcrumbs in a third bowl.

Step 4: Coat the chicken
Remove the chicken from the buttermilk, letting any excess drip off. Dip each piece first in the flour mixture, making sure to cover both sides. Then dunk it in the egg wash, letting the excess drip off, and finally press it firmly into the breadcrumbs. Don’t be afraid to really press the crumbs on—they’re what give that gorgeous crunch.

Step 5: Heat the oil
Pour vegetable oil into a large skillet, enough to cover the bottom about 1/4 inch deep. Heat over medium-high until it’s shimmering. To test if it’s ready, drop in a tiny bit of flour—if it sizzles right away, you’re good to go.

Step 6: Fry the chicken
Carefully lay the chicken pieces into the hot oil, leaving space between them so they crisp instead of steam. Cook 4–5 minutes per side until golden brown and the internal temp hits 165°F.

Step 7: Drain and rest
Transfer the chicken to a paper towel-lined plate to drain excess oil. Let it rest for a couple of minutes—it stays crispier this way.

Step 8: Toast the buns
While the chicken rests, lightly toast your hamburger buns in a dry skillet or toaster. Toasting gives a nice crunch and helps prevent soggy sandwiches.

Step 9: Make the sauce
In a small bowl, mix mayonnaise, Dijon mustard, lemon juice, and zest until creamy and smooth. Taste and adjust the lemon if you like it extra zippy.

Step 10: Assemble your masterpiece
Spread a generous layer of the sauce on each bun bottom. Place a piece of crispy chicken on top, then add shredded lettuce, tomato slices, and a sprinkle of parsley for color and freshness.

Step 11: Finish and serve
Cap it with the top bun and serve right away while everything is warm, crispy, and perfect. Trust me, these are best eaten immediately—no one likes cold soggy chicken!