This covers one cheesecake.

2 tablespoons granulated sugar
4 teaspoons cornstarch
2 (8 1/4 ounce) cans crushed pineapple in
    heavy syrup, with liquid
2 tablespoons lemon juice

In saucepan, combine sugar and cornstarch. Mix well. Stir in crushed pineapple, with liquid. Bring to a boil, stirring over medium heat. Boil 1 minute. Mixture will be thickened and translucent. Remove from heat and let cool slightly. Add lemon juice. Let cool completely. Spoon glaze over top of cheesecake.