Garlic, chili powder, and lots of fresh herbs make a wonderful marinade for the pork in this grilling recipe.
In a small mixing bowl, combine all ingredients except meat. Place meat in a large plastic bag set in a shallow dish. Pour marinade over meat. Close bag. Turn several times. Marinate in refrigerator 2 to 24 hours, turning occasionally.
Remove meat from bag. Discard marinade. Insert a meat thermometer into the thickest part of the roast. (Or use an instant-read thermometer to start checking the roast after 1 hour of grilling.)
In a covered grill, arrange preheated coals around drip pan (or follow manufacturer's directions for cooking over indirect heat on your gas grill.) Test for medium-low heat above pan. Place meat on grill rack over drip pan. Cover and grill for 1-1/2 to 2-1/4 hours or until meat thermometer registers 155 degree F. Remove roast and cover with foil. Let stand 15 minutes before carving. (The internal temperature of the meat should rise 5 degrees F upon standing, to 160 degree F.)
Remove strings and slice meat to serve. Use any leftover pork for sandwiches. Makes 12 servings.