2 Tbsp honey
1 Tbsp lemon juice
Pinch of salt and pepper less than ¼ tsp each
½ cup olive oil
1 cup fresh blueberries mashed
Whisk together vinegar, honey, lemon, salt, and pepper. While whisking, slowly pour in oil, then continuing whisking until completely emulsified, about 1 minute. Use a blender for a longer lasting emulsification. Place blueberries in a ziploc bag and mash until relatively smooth. You can also use a blender or food processor for this. Whisk blueberries into vinaigrette mixture.
NOTE: The fresh blueberries will cause this to go bad sooner than would a simple oil and vinegar dressing. However, this is pretty acidic, so it should stay good for longer than fresh blueberries would. Safely enjoy for about 2 weeks.