Using a strainer separate the dried onions from the dry powder; place the dry onions in a separate bowl. Rub the roast all over with 2 tablespoons oil, then season the pork loin with the onion soup powder, black pepper and garlic powder.
Brown the roast on all sides in hot oil then allow to cool slightly. Make small slits all over in the roast,then stuff with garlic cloves. Place the roast in the slow cooker.
In a bowl whisk the French dressing with the cornstarch until smooth then add in the cranberry sauce and dried onions. Mix until combined. Pour the mixture over and around the pork. Cover and cook on HIGH heat for 4 hours or on LOW for about 7-8 hours or until the pork reaches internal temperature of 160 degrees F.