Place 1 chicken breast half between 2 pieces of plastic wrap or waxed paper. Working from center, gently pound chicken with flat side of meat mallet or rolling pin until about 1/4 inch thick; remove wrap. Repeat with remaining chicken breast halves.
In small shallow bowl, combine bread crumbs and garlic salt. Coat both sides of chicken breast halves with flour. Dip each in egg; coat both sides with crumb mixture.
Heat oil in large skillet over medium-high heat until hot. Add chicken; cook 6 to 8 minutes on each side or until lightly browned and juices run clear.
Meanwhile, place French rolls, cut side up, on ungreased cookie sheet. Broil 4 to 6 inches from heat for 1 to 2 minutes or until toasted; remove top halves of rolls from cookie sheet. Spread bottom halves of rolls with mayonnaise; top with lettuce, tomato, chicken and cheese. Broil 4 to 6 inches from heat for 1 minute or until cheese is melted; cover with top halves of rolls.