Drain pineapple and peaches over a measuring cup, reserving 1 cup combined juice.

Whisk the reserved juice, lemon juice and cornstarch in a saucepan.

Cook over medium heat for 3 to 4 minutes until lightly glossy, then cool completely.

Fold pineapple, oranges, peaches and grapes into the cooled dressing.

Divide among eight 6-ounce cups, add one cherry to each if desired and cover.

Refrigerate for at least 2 hours and serve cold within three days.