Ahem.
Margaritas.
That is all.
Roast a cornish hen and put it on your shoulder. Show everyone what happens when Polly gives you too much lip-- er, beak. 
If you could find roast (lower) leg of sailor, it would go a long toward explaining all those wooden legs on various pirates.
Don’t forget to instruct everyone in the pirate alphabet: A B C D E F G H AYE! J K L M N O P Q AARGH! S T U …
Go with sauerkraut. 
Grog is easy enough to make, it’s a simple concoction that was intended to make the stinky water which had been stored in barrels for months both safe to drink and somewhat palatable. It’s simply 1 part rum diluted with 4 parts water, some lemon or lime juice, and (optionally) a little sugar and/or a spice like cinnamon or black pepper added. Serve at room temperature.
Make sure you have a roll or two of Bounty paper towels so everyone could have a Bounty on their heads…aarrgghh.
You put the lime in the sauerkraut, and mix it all up…
Wait, no, that’s not right.
Not a food suggestion, but …
I had the Cornish hn idea, but after it’s cooked cover it with green feathers. Or pickles.
I suggested corned beef, but nobody else seemed to get it.