调味 means 'to season' or 'to add flavor (to food)'. It is a separable verb (离合词): the object or a frequency/duration phrase can go between 调 and 味, like 调一下味 ('season it a bit') or 调过味了 ('already seasoned'). You do not put the food directly after the verb — instead say 给菜调味 or 用酱油调味.