Step 1

In a small bowl, combine the cornstarch and water. Stir until completely smooth.

Step 2

Then, add the sugar and cornstarch mixture to a small saucepan. Whisk together.

Step 3

Add 1 cup of the blueberries to the sauce pan. Then, stir to coat with the sugar mixture.

Step 4

Then, add the lemon juice, lemon zest, vanilla, and salt

Step 5

Bring the mixture to a boil over medium heat, then reduce the heat to a simmer and continue to cook for 4-5 minutes, until thickened.

Step 6

Stir in the remaining blueberries and simmer for for 4 more minutes.

Step 7

Remove from heat and cool.

Step 8

Store in the refrigerator for up to a week.