Sweet and sour crispy tofu

Methods: two spoons of soy sauce, two spoons of balsamic vinegar, two spoons of ketchup, a spoonful of sugar, a spoonful of cornstarch, half a bowl of water, tofu cut into cubes coated with cornstarch, coated with egg wash, fried until golden brown on both sides, the sauce boiled until bubbling, pour the tofu coated with sauce, sprinkled with white sesame seeds