Place whole beets (greens trimmed) in a casserole dish with vinegar, sugar, and the water. Microwave, covered, on 100 percent power (high) for 9 to 12 minutes or until tender, stirring once. Trim stem and slip off skins. Slice beets; reserve cooking liquid.
While beets are in microwave, prepare toast. Preheat broiler. Spread baguette slices with cheese. Broil 4 inches from the heat for 3 minutes or until cheese is melted and bread edges are toasted; set aside.
For dressing, whisk oil, salt, and pepper into reserved cooking liquid. In a large bowl toss beets, salad greens, and cranberries with dressing. Sprinkle with pumpkin seeds; pass toast.