Beet and roquefort salad with walnuts

8 to 10 medium-size beets
3 tablespoons red wine vinegar
3 tablespoons walnut oil
1/2 cup shelled walnut halves
1/4 pound imported Roquefort cheese
freshly ground black pepper, to taste

1. Wash beets well, and trim stems and roots without piercing the skin. Drop the beets into a large kettle of boiling salted water and cook until tender, 20 to 40 minutes, depending on the beets. Drain, cool, and peel beets, and cut into julienne.
2. In a mixing bowl toss the beets gently with the vinegar and walnut oil. Taste and add more of either if you like; there should be just enough to coat the beets. Cover and chill until serving time.
3. To serve, toss the walnuts with the chilled beets and arrange in a shallow serving bowl. Allow to return to room temperature. Crumble the Roquefort evenly over the top and grind on black pepper to taste. Serve immediately.