Learn English – Idiom/expression for changing the subject in a conversation

Is there an idiom/expression in English for changing the subject in a conversation (and if possible, in a sarcastic way)?

For example, there is an expression in Turkish: gelelim fasulyenin faydalarına. It can be translated as "let's get/come to the benefits of beans". It also has a sarcastic flavor in it.

It is used generally when you want to change the subject/topic in a conversation. There can be similar but slightly different connotations as well:

• to change the topic where you think that the conversation is boring
• to start a topic when everyone is silent or there is no substantial conversation
• to change the topic to talk about the main/important subject (and this subject is usually important to you only)

It is not getting to the point or beginning to get serious. So the following expressions don't cut it:

• let's get down to business
• let's get down to brass tacks
• let's get down to bedrock
• let's get down to nitty gritty
• let's get down to cases

_{Alternatives of the Turkish expression:}

_{– gel gelelim fasulyenin faydalarına
– gelelim kuru fasulyenin faydalarına}