You are so close, you don't even know it. I bet she's on some other message board right now with a post like "How do you ask a customer out, there's this guy and I think he likes me but he's being a sissy wimp and not asking me if I want a fish sandwich. I think if he doesn't ask me soon I'm going to write him off as a lame loser and find some other guy."
If she doesn't like fish sandwiches then you shouldn't be interested. Women are crazy enough. No need to compound the issue with a dislike of fish sandwiches.
It's a well known fact that women perceive the alpha male as the individual with the most fish sandwiches. Trust me, I know my way around the more "fish sandwich enamored" sex...