be (one's) man/woman

To be the person that can help one due to possessing something in particular, such as a skill, access to something, etc. If you need help with your taxes, Teresa's your woman—she's something of an expert. I'm trying to score tickets for the sold-out concert, and Dave told me that you're my man. If you need a file pulled, I'm your man—I manage all of the employee files.

be somebody’s ˈman/ˈwoman

be the best person to do a particular job, etc: If you need a driver, then I’m your man. ♢ If you need a good music teacher, she’s your woman.