Cut the chicken breast into bite-sized pieces.
Season the chicken breast with salt, pepper, and garlic powder.
Coat the chicken evenly with breadcrumbs.
Heat cooking oil in a pan and cook the chicken breast over medium heat until golden brown.
Slice the bread in half and toast it.
Prepare vegetables like lettuce, tomato, and pickles.
Spread mayonnaise on the toasted bread.
Place the vegetables and chicken on top of the bread.
Cover with the other piece of bread to finish the chicken sandwich.