The most common and most likely answer to this crossword clue is the 6 plus 6 letter word LARDER FRIDGE
I've seen this crossword clue in The Daily Telegraph
L
A
R
D
E
R
F
R
I
D
G
E
Buddy explains!

The straight part
We know that "Kitchen appliance" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case kitchen appliance = larder fridge.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.