Drain pineapple and reserve juice. Add juice to 1/2 cup hot water and heat to boiling. Soften gelatin in 1/4 cup cold water. Dissolve softened gelatin in hot water-juice mixture. Let cool until it starts to set; don't let the gelatin harden. Put cranberries through a grinder. Add ground berries, pineapple, nuts, and sugar to cooled gelatin mixture. Mix well. Pour into a bowl or mold. Refrigerate until completely set. Place mold in a warm water bath and run a knife around the edges to loosen. Invert onto a serving plate, garnish with parsley and a dollop of sour cream or whipped cream.