Asking for a recommendation

¿Qué me recomienda?

keh meh reh-koh-mee-EN-dah — What do you recommend?

"No conozco el menú, ¿qué me recomienda?"
I don't know the menu, what do you recommend?

Uses the polite "usted" form (recomienda, not recomiendas) since you're addressing a waiter you don't know — a nice, natural place to practice that register.

"My favorite question to ask any waiter in Madrid — it's led me to some incredible meals over the years."— Graciela