点菜 is a separable verb (离合词) that means 'to order dishes from a menu in a restaurant'. When you want to add a measure word, quantity, or duration, the two halves split apart: the verb 点 takes the complement, and 菜 moves later, as in 点一个菜 ('order one dish'), 点了几道菜 ('ordered several courses'). You never put an object between the two characters in the non-split form.