1 medium-sized tart apple (such as a Granny Smith), cored, peeled and cut into 1/4-inch-thick slices
1/3 cup apple-cider vinegar
2 tablespoons minced shallot
2 tablespoons sugar
1 1/2 teaspoons chopped, fresh rosemary
1/4 teaspoon freshly ground black pepper
2 teaspoons Dijon-style mustard
1 teaspoon soy sauce
1/2 teaspoon salt
1 tablespoon finely minced green onion
1/2 cup vegetable oil

Combine the apples, vinegar, shallot, sugar, rosemary and black pepper in a skillet; bring to a simmer. Reduce heat to low, cover and simmer until apples are tender, about 10 minutes. Remove from heat and transfer to a blender or food processor.

Add the mustard, soy sauce, salt and green onions; puree on high speed. With motor running, add the oil in a thin stream and process until emulsified (mixture will appear thick with a consistency similar to mayonnaise). Remove from blender, adjust seasonings, adding additional pepper, mustard, soy sauce or salt as needed, and refrigerate in an airtight container until ready to use. Will keep for several days.

Makes about 1 1/2 cups.