Back story below but straight to the question at the very bottom
Was at a Christmas party the other night for my university social basketball club. It wasn't a big gathering, about 20 or so, maybe a 60-40 male to female split. Anyway, one of the girls bought her bestie, who as it turns out was actually a girl from my graduating class in high school, though we'd never spoken since our school was large and kinda segregated between streams you went down in terms of studies.
After talking to everyone at the place pretty evenly at the start which I like to do since I'm a friendly guy and get along well with all these people (plus displays good social value), I settled into the 6 person section of the party that she was in. We talked together as a group and then despite the fact that all of us were still around the same table she and I spoke one-on-one for ages while they were talking about something else. I was digging her attitude and focus on her career, and I seemed to hold her attention.
Eventually the party naturally wound down and she left. Perhaps I could've (should've) asked for her number then and there. She's previously dated successful pro athletes so she's an absolutely stunning girl, maybe that got me nervous. So given the current situation:
Question: I've since friended her on facebook and want to know if there's an ideal way to approach asking her out?
I'm thinking about just being straight up saying a more literate version of "it was great chatting to you, we should grab dinner some time (reference particular conversation point about her great appreciation for japanese food and my indifference to it)". A quick approach, that at least gives me clarity of answer. It's unlikely I'd run into her anytime soon to build up a rapport in person.