Step 1

In a saucepan, over medium heat, add the blueberries, sugar, lemon juice, and half the water (1/4 cup). Cook on low to medium heat until all the sugar has dissolved. Use a vegetable masher to mash some of the fruit. Pro tip - Mashing will add a nice thicker consistency to the topping but make sure to leave some blueberries whole.

Step 2

Combine the remaining water with cornstarch. Add it to the blueberries. Continue to cook on low heat until the filling is thick and glossy. When thick enough to coat the back of a wooden spoon or spatula it's ready.Pro tip - Cornstarch can settle to the bottom of the water. So, you must stir it just before adding it to the saucepan.

Step 3

Remove and pour into a mason jar. Let cool completely or use as directed in your recipe. Pro tip - The filling will thicken as it cools so keep that in mind when you take it off the heat.