1. Preheat oven to 425 degrees. Line a large roasting pan with foil. Place the beets in the pan in a single layer. Cover the pan with foil and bake until the beets are tender, about 1 hour.
2. When beets are done, let them cool slightly. Remove the tops and slip off the skins. Cut the beets into 1/2 inch wedges.
3. In a small bowl, combine the mustard, vinegar, salt and pepper. Slowly whisk in the safflower and olive oils.
4. In a medium bowl, toss the beets with 3/4 of the vinaigrette. Arrange the endive leaves on a large plate, pour the remaining dressing on top and sprinkle with chopped chives. Add beets.