• The pork roast will probably have a thicker cut of fat on one side. I like to trim this down a little, don't remove it all. Leave no more that 1/4 inch layer of fat. This is the bottom.
• Set your meat fat side down on a large piece of plastic wrap and spread mustard over the top.
• Combine your salt, chili powder, cayenne, pepper and garlic in a small dish. Sprinkle mixture on top, rubbing into your mustard with a spoon, spreading the top and sides of your meat.
• Wrap up your meat with your plastic wrap and set in a dish to refrigerate for at least 3 hours or overnight.
• When ready to cook, preheat your oven to 325°.
• Line a shallow pan, or cookie sheet with sides, with tinfoil. Lay a metal rack on top of foil. Unwrap your meat from the plastic wrap and set on the rack uncovered, fat side down.
• Roast for 3 hours uncovered. At this point, cover your meat with 2 layers of foil and return to roast for at least another hour. At the 1 hour mark, check your meat's temperature with a meat thermometer poked right through the foil. If the meat is not quite at 190° you can return it to the oven for another hour or so. If your thermometer reads at least 190° then remove it from the oven. Keep it covered and let it rest for another 30 minutes to an hour, undisturbed.
• When it is time to serve, uncover meat, set on a plate with 2 serving forks, and pull apart into pieces as you like.

*If you opt for a larger cut of meat, say 6 lbs, double your spices and mustard and increase your cooking time to 4 hours uncovered and 2 hours covered.