In a 1-quart saucepan, combine the figs, zinfandel, red wine vinegar and the sugar. Bring the contents of the saucepan to a boil and reduce to a gentle boil until the figs are reconstituted and the liquid has reduced to a glaze, about 8 to 10 minutes. Remove the saucepan from the heat. Transfer 1/4 cup of the figs and all of the reduction liquid to a blender* with the mustard, shallots, garlic and balsamic vinegar. Blend until smooth, about 15 seconds. With the blender running, add the olive oil in a slow, steady stream, until completely emulsified and smooth. Season with salt and black pepper and transfer to an airtight, non-reactive container. Set the remaining figs aside to cool completely before assembling the salads.
To serve, place the greens in a large mixing bowl with the cooled figs, walnuts, blue cheese, prosciutto, and 1/2 cup of the vinaigrette. Season with salt and pepper and divide among 4 salad plates to serve.
*When blending hot liquids: Remove liquid from the heat and allow to cool for at least 5 minutes. Transfer liquid to a blender or food processor and fill it no more than halfway. If using a blender, release one corner of the lid. This prevents the vacuum effect that creates heat explosions. Place a towel over the top of the machine, pulse a few times then process on high speed until smooth.
Yield: 4 servings