The sheer size of Brown Sugar’s menu and the sizzling tease of the plates that come flying out of its always-busy kitchen can turn the most decisive diners into covetous rubberneckers. Fortunately, it’s hard to go wrong here, whatever the choice. Chili addicts swear by the Old Lady Spicy, a mélange of roasted Thai eggplant, peppers, green beans, and sweet basil; meeker palates shouldn’t miss the beef macadamia on gingery watercress. Need further guidance? An advance look at the restaurant’s comprehensive online menu is the smart way to winnow the possibilities.