Step 1

Bring a large pot of lightly salted water to a boil. Cook orzo in the boiling water, stirring occasionally until cooked through but firm to the bite, about 11 minutes. Drain and transfer to a large bowl. Add mandarin oranges, pineapple chunks, crushed pineapple, and maraschino cherries to orzo.

Step 2

Combine juice from mandarin oranges, juice from pineapple chunks, juice from crushed pineapple, sugar, eggs, and flour in a saucepan over low heat; cook, stirring often, until sauce is thickened, 5 to 7 minutes. Remove sauce from heat and cool, about 30 minutes.

Step 3

Pour cooled sauce over orzo mixture and toss to coat. Refrigerate until flavors blend, 8 hours to overnight. Fold whipped topping into orzo mixture before serving.