The most common and most likely answer to this crossword clue is the 6 letter word LARDON
L
A
R
D
O
N
Buddy explains!

The straight part
We know that "bacon cube" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case bacon cube = lardon.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.
What does LARDON mean?
LARDON noun- A meat strip used for larding, especially salted pork.