Mustard-Glazed Rack of Pork with Grilled Pineapple

This is truly an impressive presentation. Like a standing rib roast of beef, a rack of pork is regal, with its bulging eye, crusted with spices, herbs, and mustard, perched atop an arch of bones. A 4-rib rack, weighing 3½ pounds, will feed 6 people amply, but if you want to give each person a bone you will have to plan on almost a pound per person, which will come out to about 10 ounces of meat per serving. A roast of that size will not take any longer to cook, since it will have approximat