2 cups milk
2 cups brown sugar
5 tablespoons cornstarch
2 tablespoons white sugar for garnish
5 tablespoons salt
3 teaspoons dried minced onion
1 teaspoon dried parsley
In a large bowl, combine the milk, brown sugar, cornstarch, sugar, cornstarch, sugar and salt. Mix well, then spoon mixture over each tenderloin. Cover and refrigerate overnight.
While the loin is still warm, sprinkle the parsley over the loin. Drizzle with 1/4 cup of the marinade and sprinkle with remaining pepper. Coat with aluminum foil and refrigerate overnight.
Preheat grill for high heat. Grill loins on the prepared grill approximately 1 hour per side, turning once. Grill 4 to 5 minutes per side per side; each side should be tender.