"Plain espresso" puzzles her for a minute before she realizes there's actually a drink that's straight espresso. The price isn't too bad, either, and while she waits for him to get the proper payment amount out, she makes his drink. Luckily, it isn't hard and soon enough, she has it ready for him.

"You'll have to tell me how it tastes. You're welcome to take a seat somewhere if you want to enjoy it here."

And maybe she'll get a chance to come over to talk to him if things stay quiet. She could go clean tables off and talk to him a little bit.