I was in Boston last week and ate at The Helmand. The Helmand in Baltimore was my first taste of Afghan food and will always be my favorite. I had the pumpking appetizer which was heavenly. Both my boyfriend and I had dishes we didn't like as entrees because they were more spicy than we are used to. I usually go with the Kabuli (lamb with challow topped with raisins and glazed carrots) but I wanted something different. So while we disappointed in the dishes, it wasn't because they weren't good; we, personally, didn't like the taste while I'm sure others would. We were right by the oven and got the nan right away and it was awesome. It seemed full and everyone seemed happy with their meals. I didn't notice parking because we took a taxi from the Copley Square.
I went there about a month ago, and honestly everything we ate was like a revelation. I've been unable to get their food out of my mind ever since. The nan, straight from the tandoor, was fresh, dense and tasty, and the chutneys and raitas that accompanied were perfectly spicy and piquant. The bourani, particularly the potato one, was amazing, and the pumpkin appetizer was one of the best examples I've ever had of what can sometimes come off as a weak vegetable. We had a special of a soup called aush, made with vegetables and fresh noodles and yogurt which was totally out of this world. The vegetables melted together with the yogurt for a surprisingly luscious taste experience. I can't really remember the rest of the stuff that we had (and it was all vegetarian, so I can't advise about the quality of the meat), but I would guess that just about anything you have there will be good, and some things truly great. The dessert was great too. Good luck!