To crush the corn flakes; place them inside a plastic bag and finely crush them with a rolling pin (or mortar and pestle).
Place chicken breasts inside a plastic bag and pound out until thin.
Crack the egg into a bowl; add salt, black pepper, garlic powder, mayonnaise and lemon juice; beat well.
Season both sides of chicken breasts with black pepper and salt.
Spread the all-purpose flour and crushed corn flakes in 2 separate plates. Coat chicken breasts in all-purpose flour, turning to coat. Dip them in the egg mixture, turning to coat. Then dip the chicken breasts in the crushed corn flakes, turning to coat.
Heat oil over medium-high heat in a frying pan. Place the chicken breasts (breaded with crushed corn flakes on both sides) into the pan and reduce heat to medium-low. Fry until they are cooked through and lightly golden brown on both sides. Place them on paper towel to absorb extra oil. Serve immediately.