be the apple of someone's eye
in apple-pie order
bring home the bacon
Go bananas
Be full of beans
Spill the beans
Take the bread out of somebody's mouth
That takes the biscuit!
Butter (somebody) up
Butter wouldn't melt in your mouth.
A piece of cake
Sell like hot cakes
Champagne taste on a beer budget
Big Cheese
be like chalk and cheese
Get a second bite/ two bites at the cherry
Useful as a chocolate teapot
Sharp cookie
Cream rises to the top 
That's the way the cookie crumbles!
as cool as a cucumber
A bad egg  
teach one's grandmother to suck eggs
you can't make an omelette without breaking the egg.
Over-egg the pudding  
Have all your eggs in one basket
Low-hanging fruit  
as nutty as a fruitcake
it smells fishy
To have bigger fish to fry
play gooseberry
Sour grapes
Money for jam
stew in one`s own juice
half a loaf is better than none
Square meal 
one man's meat is another man's poison
Milk of human kindness
It's no use crying over spilt milk.
make mincemeat of someone or something
As keen as mustard 
Mutton dressed (up) as lamb
A sledgehammer to crack a nut
Go nuts 
Olive branch 
To know your onions
Like two peas in a pod
as thick as a pea soup
Eat humble pie
Pie in the sky 
Have a finger in every pie
In a pickle 
Plum job
Plum in your mouth 
as busy as popcorn on a skillet
Drop someone (or something) like a hot potato
a couch-potato
The proof of the pudding is in the eating. 
It sticks to your ribs
Back to the salt mines 
Take something with a grain of salt
rub salt in (someone's) wound
packed in like sardines
from Soup to nuts
too many cooks spoil the broth/stew
(not my) cup of tea
as warm as toast
Hold water 
Make your mouth water
(You can't put) new wine in old bottles

Collected by Allison Leung and Rachel Yang.