Answer:
Sirve
Step-by-step explanation:
Sirve is the third person simple present form of the verb "servir" (to serve). The sentence translated says My mother ___ many tasty dishes in my birthday party. So the best fitting verb would be to serve. Then we conjugate the verb appropriately, since "servir" is an irregular verb we need to look up the correct conjugation, which is "sirve" in this case.