All too often, and especially in the Bay Area, food is treated with so much reverence that the festive nature of dining out is smothered under a blanket of unction and parsley oil. But at B44, an ever-hopping tapas joint in the Financial District, fun is an infectious constant. That's especially true after your plates of Catalan delicacies have been cleared away and it's time for the meal-closer known as Mel i Mato. It revolves around el porronet, a bota bag not unlike the one you used to shoot streams of wine into your mouth the last time you were hiking through the Pyrenees. Here it's filled with cream sherry and arrives at your table accompanied by a platter of soft, milky quesa blanca studded with walnuts and drizzled with honey. The idea is to stick a forkful of the sweet, nutty cheese into your mouth, let it intermingle with your taste buds a bit, and then squeeze a blast of sherry in there as a concluding culinary motif. The result is a terrific combination of flavors and textures, but more than that it's a wonderfully goofy way to put the pizzazz back into suppertime.