Example sentences from the web:

• Get yourself a piece of bread, I’ll make you a chip butty.
• Give us an egg butty and don’t break the yolk.
• “What’ve you got for your dinner?”
  “Cheese butties.”

Notice that you could also hear the term ‘sarnie’ (British slang) referring to a sandwich.

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Example sentence from the web:

• Do us a favour, pop to the shops and get us a sarnie.