All these idioms use food items in some way.
be the apple of someone's eye = be someone's favourite person: "She's the apple of her father's eye."
in apple-pie order = in perfect order: "Her house was in apple-pie order, with nothing out of place."
be as nice as pie = be extremely nice and charming, so that you can fool people: "She can be as nice as pie, but don't trust her!"
eat humble pie = have to take back what you said, because you have been proved wrong: "He'll have to eat humble pie now. Serve him right – he tried to make us all look bad."
have your fingers in every pie = be involved in many different things: "You can't do anything without him knowing – he has his fingers in every pie."
a piece of cake = be extremely simple: "This program is a piece of cake to use."
sell like hot cakes = sell quickly in large quantities: "His book is selling like hot cakes."
full of beans = be full of energy: "You're full of beans today – it's nice to see you so lively!"
beef about something = complain about something: "He's always beefing about the pay."
beef something up = give something extra appeal: "If we beef up the window display, more people might come into the shop."
be your bread and butter = be your main source of income: "Although they run a taxi service, car sales are their bread and butter."
be like chalk and cheese = be completely different: "I don't know why they got married – they're like chalk and cheese."
be like peas in a pod = be identical to someone: "Those two are like peas in a pod."
cheesy = predictable and unimaginative: "I don't want to see that film again – it's really cheesy."
sour grapes = say something bad because you didn't get what you wanted: "Don't listen to him complain – it's only sour grapes because you got the job and he didn't."
play gooseberry = go somewhere with a couple who would prefer to be on their own: "I'd rather not come to the cinema with you two – I'd just feel I was playing gooseberry."
a couch-potato = someone who never goes out or exercises: "He watches TV all day – what a couch-potato!"
like butter wouldn't melt in your mouth = appear innocent: "When I asked her about the missing money, she tried to look like butter wouldn't melt in her mouth."
bring home the bacon = earn money for necessary things, like food: "He brings home the bacon in that family."
the way the cookie crumbles = the way things are: "I'm sorry I didn't get the promotion, but that's the way the cookie crumbles."
have someone eat out of your hand = have control over someone: "He has her eating out of his hand – it's sad."
eat someone out of house and home = eat a lot of food: "Her children eat her out of house and home."
eat into your savings = spend some of your savings: "We can't afford a new car, unless we eat into our savings."
eating for two = be pregnant and so eating more: "Good news, darling. The doctor says I'm eating for two now."
eat your heart out! = telling someone they should be jealous of you: "I'm going on holiday to Jamaica – eat your heart out!"
not your cup of tea = something that you don't like much: "Football isn't my cup of tea."
a square meal = a filling meal: "You need a square meal after all that exercise."
it smells fishy = something that is suspicious: "He wants to do all the housework for you? That smells fishy to me!"
small fry / small beer = something or someone unimportant: "Sales last year are small fry compared to now – we're doing really well."
roll out the barrel = prepare to have a good time: "Roll out the barrel – we're celebrating our exam results."
rhubarb, rhubarb = saying something completely unimportant: "There's that politician again on televison – rhubarb, rhubarb."