Addie's - it's in a weird, random place kind of across from the mall. In the summer, it's actually surprisingly romantic even though you are overlooking the pike. The make a cute outside seating area with what they have. The food was wonderful as was the wine.
Also Mykonos is a great place for a romantic dinner.
Addie's - it's in an old house, very cozy and generally good food. I don't recall how vegetarian friendly they are but it strikes me as a place that would be accommodating, esp. if you called ahead of time to ask.
Il Pizzico - great pastas with lots of vegetarian options. Native Italian speakers abound, so you know it's good (despite ugly strip mall decor on outside). The pastas are SO delicious!
Cava for greek small plates. There is Le Palais in the Kentlands for French, but I do not know if they are open for lunch. La Flor de la Canela for Peruvian. Maybe Tandoori Nights for Indian. Nick's Chophouse for steaks and seafood, probably good salads, too. I'm not sure how veg-friendly they are, but you can look at their menus online or call ahead to check. Adding... Black Market Bistro might be nice, too.
Nick's Chop House
700 King Farm Blvd, Rockville, MD 20850
La Flor De La Canela - CLOSED
117 N Frederick Ave Ste 3, Gaithersburg, MD 20877
9713 Traville Gateway Dr, Rockville, MD 20850
304 Main St, Gaithersburg, MD 20878
106 Market St, Gaithersburg, MD 20878