2 cups blueberries
1/2 cup water
1/2 cup sugar
2 tablespoons lemon juice
2 tablespoons cornstarch, mixed with 2 tablespoons cold water
Zest of 1 lemon
Combine the blueberries, water, sugar and lemon juice over medium heat. Stirring, bring to a low boil. Whisk cornstarch with 2 tablespoons water. Carefully stir into blueberry mixture. Simmer until thick, about 5 minutes.
Remove from heat and gently stir in lemon zest.