Hi,
It has been numerously mentioned in this forum, I think, that with the use of the words like 'before' and 'after', there is no need to resort to using past perfect.
Can it be also apply to the past perfect continuous tense?
1. I had been fixing my meal before Jane walked in.
No need for this since like in "I had worked on this project before Jane walked in" where "had worked' could be replaced with 'was' with seemigly no difference, the sequence of events can be sufficiently understood.
2. I was fixing my meal before Jane walked in.
Both no. 1 and 2 are saying the same thing, that is, my fixing of my meal occurred before her waking in.