Follow these simple steps to create your Crispy Lemon Pepper Chicken Sandwich:

1. Marinate Chicken: In a large bowl, combine the buttermilk, lemon pepper seasoning, garlic powder, and onion powder. Add the chicken breasts, ensuring they are fully coated. Cover and refrigerate for at least 30 minutes.

2. Prepare Coating: In a shallow dish, mix together the flour, breadcrumbs, salt, and pepper.

3. Heat Oil: In a large skillet, pour enough vegetable oil to cover the bottom of the pan. Heat over medium-high heat until shimmering.

4. Coat Chicken: Remove the marinated chicken from the refrigerator. Dredge each piece in the flour mixture, ensuring an even coating.

5. Fry Chicken: Carefully place the coated chicken breasts in the hot oil. Cook for about 5-7 minutes on each side or until golden brown and cooked through. Use a meat thermometer to ensure they reach an internal temperature of 165°F (75°C).

6. Drain Chicken: Once cooked, transfer the chicken to a paper towel-lined plate to drain excess oil.

7. Assemble Sandwich: Toast the sandwich buns lightly. Spread mayonnaise or your favorite sauce on both halves of the bun. Add a layer of lettuce, a slice of tomato, and top with the crispy chicken.

8. Serve: Place the top half of the bun over the chicken, and your Crispy Lemon Pepper Chicken Sandwich is ready to enjoy!