Please pass the army and navy for my mashed potatoes.
army and navy
idiom Slang
Cockney rhyming slang · East London
gravy
Origin
As gravy was plentiful at mealtimes in both services.
The roast beef is quite dry, so I would appreciate some army and navy.
He poured a generous amount of army and navy over his meal, savoring the rich flavor that completed the dish.