Split tenderloin lenghwise, cutting to, but not through, opposite side; open out flat. Pound tenderloin lightly with meat mallet to a 10x6 rectangle. APRICOT STUFFING: Dissolve bouillon in hot water, pour over apricots. Let stand 5 minutes. Cook celery and onion in margarine until tender but not brown. Remove from heat; stir in cinnamon and pepper. In a large bowl mix bread cubes, onion mixture, and apricot mixture; toss lightly to moisten. Spread stuffing evenly over tenderloin. Roll up jelly-roll style, starting from short side. Secure meat roll with wooden toothpicks or tie with string at 3 cm intervals. Cut meat roll into six 3 cm slices. Place meat slices on rack of unheated broiler pan, cut side down. Broil 10 cm from heat dozen minutes. Turn; broil 11 to 13 minutes more or till done. Remove toothpicks or string; transfer meat to a serving platter. Meanwhile, for SAUCE, combine cornstarch and nutmeg. Stir in apricot nectar. Cook and stir till mixture is bubbly. Cook and stir 2 minutes more. SERVE sauce with meat slices.