Frank Bonanno and his crew at Mizuna do just about everything pretty darn well, but the one thing they do far and away better than any other kitchen in town is sweetbreads. Thymus glands are devilishly hard to cook right; they require careful handling and perfect timing in the pan. But in expert hands, the result can be a sublime bit of charcuterie that -- like the preparation of foie gras or the proper handling of truffles, both of which Mizuna also does admirably well -- can be held up as a benchmark achievement. Mizuna's sweetbreads are a fine measure of a galley and crew that consistently bring their A-game every night of the week.