Tropical Ambrosia

1 (15 1/4 oz.) cans pineapple chunks, divided

1 (11 oz.) can mandarin oranges

1 (6 oz.) pkg. orange-pineapple gelatin

1 pt. orange sherbet

1 (8oz.) ctn. sour cream

1 c. flaked coconut

1 c. miniature marshmallows

Drain pineapple and oranges, reserving liquid. Add enough water to liquid to make 2 cups. Bring liquid to a boil in a medium saucepan; add gelatin and stir until dissolved. Remove from heat. Add sherbet and stir until melted. Add oranges and 1/2 the pineapple. Pour into 6 cup ring mold and chill until firm. Unmold onto serving platter. Combine sour cream, coconut, marshmallows, and remaining pineapple. Spoon into center of gelatin ring. Serves 10 to 12.