- 1/4 cup Sherry wine vinegar
- 1 large shallot, chopped
- 2 teaspoons Dijon mustard
- 1/2 cup olive oil
- 1/2 cup crumbled blue cheese
- 12 medium red-skinned potatoes, unpeeled (about 2 3/4 pounds)
- Additional olive oil
- 2 bunches watercress, stems trimmed
- 3 green onions, chopped
- Combine vinegar, shallot, and mustard in medium bowl. Gradually whisk in oil. Mix in cheese. Season vinaigrette to taste with salt and pepper.
- Cook potatoes in large pot of boiling salted water until almost tender, about 16 minutes. Drain; cool completely. Cut potatoes into 1/4- to 1/2-inch-thick rounds. Brush rounds on both sides with oil; sprinkle with salt and pepper.
- Prepare barbecue (medium-high heat). Arrange watercress on platter. Grill potatoes until golden and cooked through, about 3 minutes per side.
- Mound warm potatoes atop watercress; sprinkle with green onions. Spoon vinaigrette over potatoes.