Brown roast on all sides in hot oil in a heavy skillet over medium heat.
Place browned roast on a rack in a Dutch oven or in a roasting pan with a tight-fitting lid. Combine pineapple juice, soy sauce, brown sugar, vinegar and garlic salt and pour over roast. Cover tightly.
Bake in the oven at 325 for 60-70 minutes (to medium doneness) or until tender.
Remove roast from roasting pan and cover to keep warm. On top of range, bring liquid in pan to a boil. Add cornstarch mixture and cook for 2 minutes or until sauce thickens. Slice meat and serve with wild rice and sauce.