I work in a restaurant. Sometimes I need to inform English-speaking customers that all of their dishes have been served. What are some common phrases that I can use?
What happens frequently in American restaurants is the waiter/waitress will ask after serving the last plate of food, especially if it's a large party
I think that's everything (looking around the table)
Does everyone have everything?
or something to that effect, which is asking three things at once
1) Does everyone have their food?
2) Is anything missing?
3) Is there anything else you might need? (i.e. condiments)
If something is missing or believed to be missing the customer will point it out or ask for it
After a few minutes, the waitress/waiter will usually circle back and ask
How is everything?
to check that the food was prepared as desired
In high-end restaurants what may be said after serving the main course is
Please enjoy your meal
as the wait staff deferentially move away from the table
If everyone at the table has a plate, simply asking
"Can I get you anything else?"
implies that you believe everything has been delivered to the table. This question gives the guest(s) the opportunity to notify you if anything actually was missed. It also gives the opportunity for guests to make adjustments: "Can I get a hot sauce to go with this?"
"Is there anything else, Sir/Ma'am?", (to clarify if something's amiss or if a customer needs something - usually the last spiel in any customer service related work)
About your inquiry, you can simply notify them using this line:
"Sir/Madam, the order is now complete. Is there anything else I can help you with?"
Kindly note that there are other possible ways to notify/inform.
You don't need to explicitly say, "All dishes have been served." If you ask
Would you care for some desserts?
Would you like to have some dessert?
They would have the same meaning as "All your dishes have been served."
Dessert is served at the end of a meal unless specifically asked by customers during a meal.