Pear, Endive, Stilton and Walnut Salad with Pear Vinagarette

*For the Vinagarette, peel, core and coarsely chop the two soft pears. Combine with the vinegar in a heavy saucepan. Cook over medium heat until the liquid is reduced by half. Process in a food processor until smooth. Add the honey and process again until smooth. Add the walnut oil gradually, processing constantly until smooth. Season with salt and white pepper. Store in an airtight container in the refrigerator for up to one week. Stir to mix before using. For the salad, cut the firm pears into thin slices. Cut the endives crosswise into thin slices. Combine the pears and endives in a bowl and add the desired amount of vinagarette, toss to coat well. Arrange on the serving plates and top with walnuts and cheese. Garnish with grapes cut in half.