The most common and most likely answer to this crossword clue is the 7 letter word TOTTING
T
O
T
T
I
N
G
Buddy explains!

The straight part
We know that "doing the same as Steptoe & Son" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case doing the same as steptoe & son = totting.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 TOTTING mean?
TOTTING verb- To sum or total.
- To mark (a debt) with the word tot (Latin for "so much"), indicating that it was good or collectible for the amount specified.
- The act of totting or adding up; an addition.