A passion for dim sum is like any great love affair. You plan the next encounter before you're even out the door, you vividly go over each feverish moment, and this is the hardest partyou learn to say no. To say yes too often is to diminish the experience. You can't just grab at every steamy dumpling that rolls by (get your mind out of the gutter; we're only talking about dim sum now). In our younger, less sophisticated days, we'd make puppy eyes at each delicious dish, offer an unequivocal "sure!" to every plate proffered. We soon learned the error of our waysdo you really want to stuff yourself on rice porridge and taro puffs when meltingly tender duck and roasted broccoli are just moments away? At Lu Lu, each cart that trundles past is packed with new temptations. We could make a whole meal out of dumplingspork dumplings, shrimp dumplings, beef dumplings, tender Shanghai dumplings that hold both soup (!) and meat. Sometimes we throw caution to the wind and eat dessert right in the middle of the mealwe don't want to take the chance that those amazing red-bean-paste buns won't come around again. Maybe we'll pass on the next round, pace ourselves. Or maybe we'll say to hell with it, and take every single dish in sight. When dim sum's involved, our actions become unpredictable. Love's funny that way.