Instructions

1. Cut butter into 1 Tbsp. portions and place in the refrigerator to keep cold.

2. In a small saucepan over medium heat bring blueberries, vinegar, shallot, garlic, and rosemary to a simmer. Cook until blueberries pop and release juice, about 3 minutes.

3. Strain mixture through a fine mesh strainer. Discard solids and return mixture to saucepan.

4. Add white wine and return mixture to a simmer over medium heat. Simmer to reduce by half or even more.

5. Remove from heat. Immediately whisk cold butter into mixture, one Tbsp. at a time, until all the butter is melted and the mixture is emulsified and creamy.

6. Season to taste with salt and freshly ground black pepper.

7. Serve blueberry beurre blanc immediately or keep warm over low heat for up to an hour, whisking frequently.