Step 1

Add blueberries, 1 cup juice and sugar to a small saucepan, stir. Bring to a simmer over medium-high heat.

Step 2

Reduce heat to low and let simmer 6 - 10 minutes, stirring occasionally, until many of the blueberries have burst.

Step 3

In a small bowl whisk together remaining 2 Tbsp juice with the cornstarch then pour into pan. Let simmer 1 minute longer to thicken while stirring constantly.

Step 4

Remove from heat. Stir in lemon juice.

Step 5

If desired press and strain through a mesh sieve to remove skins, blitz in a blender (be sure to remove lids center insert and cover with a towel to blend since it's a hot liquid), or serve as is.