For dressing, in a screw-top jar, combine Blueberry Vinegar, walnut or olive oil, salt, and pepper. Cover and shake well. Chill, if desired. Makes 1/3 cup.
Combine greens, blueberries, walnut halves, cheese, and snipped chives or green onion tops in a large bowl. Pour half of the dressing over salad. Toss lightly to coat. Divide salad mixture evenly among four bowls. If desired, garnish with fresh blossoming chives. Makes 4 side-dish servings.
Combine 3/4 cup blueberries with sweetened rice vinegar in a stainless-steel or enamel saucepan. Bring to boiling; reduce heat. Simmer, uncovered, for 3 minutes. Stir in honey. Remove from heat. Set a fine-mesh strainer over a clean pint jar or bottle. Pour mixture through, pressing gently with the back of a serving spoon to express liquid. Discard remaining solids. Add another 3/4 cup blueberries to the jar or bottle. Cover tightly with a nonmetallic lid (or cover with plastic wrap and tightly seal with a metal lid). Store vinegar in a cool, dark place for up to 6 months. Before using vinegar, drain and discard berries. Makes about 1 cup.