Lechon, a Filipino tradition, is a whole pig roasted on a spit over a fire. While lechon is similar to other styles of roasting pigs, the bright red skin color and stuffing ingredients distinguish this Filipino preparation method from other styles. You can feed a large crowd with a suckling pig that weighs 100 pounds or less, but you're likely to attract a few more guests as the aroma of roasting pig flows through your neighborhood. Ask your butcher, a local farmer or meat supplier for help finding a whole pig.
Start a fire with wood in the roasting pit, using hardwoods such as oak that burn hot over a long time. You can add common smoking woods for flavor, such as apple or pecan. Chop plenty of wood beforehand so you can add it as the fire dies down. If you can't borrow or rent a rotisserie barbecue pit, scrape away grass to bare soil and stack cinder blocks to make a pit. Face the cinder block holes toward the center of the pit.
Push a steel pipe or bamboo pole through the pig's mouth and out the back side, cracking the hip bone if needed to work the pole through the exit hole. Gather the front legs and back legs in pairs; tie them around the pole with non-galvanized metal wire.
Season the inside of the pig with your choice of spices and seasonings. Seasonings vary across the Filipino culture, with some preferring only to rub the cavity with salt and pepper. Other options include filling the cavity with onions, whole garlic heads and lemongrass, or a combination of onions, taro and bananas. Sew the cavity closed with the same wire used to tie the feet to the pole. This requires a large needle to puncture the skin. You might have success with a large sewing needle, or make your own needle from a steel spike with a hole drilled in one end for threading the needle.
Brush soy sauce generously on the skin, covering the hog from head to tail and back to hooves. Soy sauce is the Filipino trick to achieving red, rather than brown, skin when cooked. In addition to applying it before roasting, you can baste the hog with more soy sauce as it cooks.
Set the pig in place over the fire pit. Slip the ends of the pole in the cinder block holes, or lock them into place in a barbecue pit that might have arms or slots to hold the pole. Turn the hog so the back faces up and lock the pole in place. If you built a cinder block pit, the pole will want to turn so the back faces down. Chock the pole against the side of the cinder block hole with a rock or brick.
Rotate the hog once every 20 to 30 minutes to cook it evenly. This isn't necessary with barbecue pits that have an electrical spit that rotates continuously.
Roast the pig for at least four hours or until it reaches an internal temperature of at least 145 degrees Fahrenheit. Insert a meat thermometer in the center of the meat to check the temperature. You must check several parts of the pig -- the hams, the shoulders, the loin -- to ensure it all reaches the optimum temperature. Exact cooking times vary greatly depending on the size of the pig and the heat from the fire. A meat thermometer is the best way to determine whether it is done, but look for signs such as crisp, red skin to tell if it's close to done.
Remove the pole and pig from the roasting pit and set it on a table. Spread newspaper or butcher's paper to protect the table top. Let the pig rest for about 15 minutes before cutting into the meat. You can carve the meat yourself, if desired, but in Filipino tradition, guests usually help themselves to whichever part of the pig they prefer.