1/2 fresh pineapple, cut into 1/2-in. chunks (4 cups)
4 medium red apples, cored and cut into 1/2-in. chunks (4 cups)
1 cup red seedless grapes, halved
2 tsp poppy seeds
3/4 cup orange juice, or pineapple juice
1 tbsp butter
1 tbsp granulated sugar
1 tbsp water
2 tsp cornstarch
1/2 cup plain or fruit yogurt, (optional)
In a large bowl, toss together the pineapple chunks, apple chunks, grapes and poppy seeds. Set aside.
In a small saucepan, combine the orange or pineapple juice, butter and sugar. Bring to a boil over medium heat. Lower the heat to a simmer. In a small bowl, stir together the cornstarch and the water, then whisk into the simmering juice mixture and continue to cook, stirring constantly until the mixture becomes glossy and thickens. Remove from heat and let cool to room temperature.
Add cooled juice mixture to the fruit mixture and toss until everything is evenly coated. Stir in optional yogurt if you want a creamy dressing. Cover and chill until ready to serve.