Clue: Cross head cooks with buns for first mate (2-7)
Answer: EX-HUSBAND
Explanation: Definition: first mate
An anagram ('cooks') of X ('cross') plus 'head' plus 'buns'. We had a complaint just a couple of days ago from someone whose first mate was not his (in that case) ex. However, with Enigmatist I will take whatever I can get to get a start!