Prepare Blueberry Puree:

In a blender, combine the blueberries and sugar (if using). Blend until smooth. You can strain the puree through a fine sieve to remove the skins if you prefer a smoother texture.

Assemble the Mimosas:

Pour about 2 tablespoons of the blueberry puree into each champagne flute.

Add orange juice to fill about one-third of the glass.

Top off with champagne or sparkling wine, pouring gently to avoid too much foam.

Stir gently to mix the layers.

Garnish and Serve:

Garnish with a few whole blueberries and a sprig of mint if desired.

Serve immediately and enjoy.