Check out San Francisco's Chinatown for some decent Chinese food. There are countless restaurants to choose from and it's actually great grocery shopping there. The vegetables, fruits, and meats are very fresh and better quality than what chain grocery stores have to offer. It's walking distance from Union Square (20-30 minutes? hey you can walk off the food) and Little Italy as well. All of this and virtually all of San Francisco is accessible by buses and BART, the wonderful railway transportation.