2. Dump mixture on the counter and roll and scrape two more times to incorporate shortening. Return to bowl, freeze 5 minutes more. Add water-vinegar mixture to bowl; toss with a fork. Press a few tablespoons of the mixture in your hand. If it clumps, you are okay; if it crumbles, add water a teaspoon at a time until mixture clumps. Dump onto the counter and bring together with your hands. Knead only once or twice, just to form a mass that sticks together. Divide into 2 flat rounds, one just slightly larger than the other. Wrap each piece in plastic wrap and refrigerate at least 2 hours before rolling.
Adam Rapoport, editor in chief of Bon Appetit magazine and the website www.bonappetit.com, knows his way around a grill. He has edited an entire book on the subject: The Grilling Book: The Definitive Guide from Bon Appetit.