SF near Union Square visit

I will be attending the JP Morgan Healthcare conference in January for an entire week. (Sorry, I’ve heard how much locals hate that conference) and because I’ve never been to SF, I would appreciate recommendations for both easy to grab lunches and nice sit down dinners. I am going with my husband, so romantic dinners included.
I took the liberty of reading some of reviews online for various places in Mission Hill. It seems that Al’s deli may fit the bill for some meals, although it may be a bit far.
Thanks in advance

The SF Chronicle recently ran an article about eating around Union Square.

Perfect! Thanks