I'll Sing You Jam O

I'll sing you jam O
Green grow the rushes O
What is your jam O
Jam is jam and all the same
And ever more shall be so
I'll sing you beans O
Green grow the rushes O
What is your jam O
Pork and beans in a little round tin

Sauce on top and in between

Also:
Marg marg margarine
Prunes in a sea of custard
Roast beef cooked in a baby's bath
Cocoa in the evening
Enos after every meal