It was a very hot day for Portland, and I didn't really want to add to the heat by warming up my kitchen. With fresh blueberries, herbs in the garden, plenty of greens on hand, and a full pantry, I didn't need any heat.
The key component in this vinaigrette is blueberry syrup. I made some a few weeks ago by putting a 2 pints of blueberries and a cup of sugar into a food processor and pulsing a few times to purée roughly. I put the purée into a saucepan over medium-low heat, tasted and adjusted the sugar, then simmered for about 30 minutes. I poured the simmered pulp into a colander lined with two layers of cheesecloth and let it drain. The remaining pulp went into the composter, while the syrup went into a small glass container in the refrigerator, where it sat until I remembered it.
Making a vinaigrette is quite simple when you know the correct ratio of oil to vinegar, 3:1. If you didn't know that ratio, or you did but you want more of that kind of handy information, you really must get yourself a copy of Michael Ruhlman's Ratio. I didn't follow the 3:1 ratio strictly, because of the lack of acidity in the ingredients I used for this vinaigrette.
2 teaspoons fresh blueberry syrup
1 teaspoons balsamic vinegar
1 teaspoons riece wine vinegar (unseasoned)
4 teaspoons extra virgin olive oil
2 leaves spearmint, minced
salt and pepper to taste
I added fresh blueberries, shredded mint, and diced red pepper to the mixed greens and herbs I had on hand. Simple, refreshing, and with the mint, cooling on a hot day.