Bite off more than you can chew
To physically bite too much food at once
To take on a task that is more difficult than you can handle
Couch potato
A potato on a couch
A lazy person
Eat humble pie
Admit you were wrong or humbled
Eat a pie made of humble ingredients
Butter someone up
To physically butter someone
To flatter someone to gain favor
The icing on the cake
An extra good feature that makes something even better
The frosting that goes on baked goods
Full of beans
Energetic and lively
Full of literal beans
Cool as a cucumber
Very calm and composed
Literally cool as a cucumber
Sour grapes
Grapes that are sour to taste
Pretending to despise something you can't have
Not worth a hill of beans
Not tasty
Not worth much
Food for thought
Something to think about
Actual food to eat
Take with a grain of salt
Add salt to food
Be skeptical about something
That's the cherry on top
A dessert topping
An extra good feature that completes something
Too many cooks spoil the broth
Having many people working on something can ruin it
A soup gets too salty when too many cooks are involved
A piece of cake
A slice of cake
Something very easy
Bring home the bacon
To earn money to support a family
To cook bacon for everyone
Spice things up
Add spices to food
Make more exciting
Go nuts
Eat nuts
Become crazy or excited
The apple doesn't fall far from the tree
Children resemble parents
Apples grow underneath trees
Spill the beans
To reveal a secret
To spill a pot of beans on the floor
In a pickle
In trouble
In a brine jar