Season chicken with salt and lemon pepper seasoning.
Let marinate for 15 minutes at room temperature.
Set up breading station with three shallow dishes.
Put flour in first dish with seasonings mixed.
Beat eggs in second dish until smooth.
Combine panko breadcrumbs with remaining lemon pepper seasoning.
Dredge chicken in flour mixture first completely.
Dip into beaten eggs covering all surfaces.
Press into seasoned breadcrumbs coating both sides thoroughly.
Heat oil to 350°F in large skillet.
Fry chicken for 4-5 minutes per side.
Cook until internal temperature reaches 165°F safely.
Remove and drain on wire rack briefly.
Toast brioche buns until golden brown color.
Spread mayonnaise on both bun halves generously.
Layer lettuce, tomato, and crispy chicken together.
Serve immediately while chicken stays hot and crispy.