2. With the skin on, cut the shallots in half lengthwise. Spray a baking sheet with non-stick spray. Drizzle the shallots with a bit of the olive oil and place them on the baking sheet cut side down.
3. Roast in the oven until the shallots are very soft, about 20 to 30 minutes.
4. When the shallots are cool enough to handle, remove the skin and the root end. Puree the shallots and salt in a food processor.
5. Add the mustard and puree. Add the vinegars by the tablespoon, pureeing after each addition.
6. With the motor running, add the olive oil and stock slowly through the feed tube.
7. Stir in the chives and pepper. Adjust the salt and pepper to taste.