Qué tal is one of the first phrases that you will notice if you are in Spain. It is used most commonly when greeting people informally, to ask how they are or how things are generally. e.g. Hola, ¿qué tal?
It can also be used to ask how something is or was, such as some food or a holiday. It can be used without a verb if it is obvious what is being talked about.
¿Qué tal la comida?
¿Qué tal anoche?
¿Qué tal tus padres?
¿Qué tal las vacaciones?