right up your alley
right up (one's) alley
Ideally suited to one's interests. Anna loves watching movies, so I'm sure she'll go to the film festival with you—that's right up her alley. This course seemed right up my alley when I signed up for it, but it ended up being dreadfully boring.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
right up your alleymainly AMERICAN
If something is right up your alley, it is the kind of thing you like or know about. This should be right up my alley but, despite the film's special effects, I found it rather boring. I thought this little problem would be right up your alley. Note: You can also say that something is right down your alley. I'll need whatever information you can turn up within the week. This case seems right down your alley. Note: The usual British expression is right up your street.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012