Roast beets for 45 minutes to an hour at 400F until tender. (I find the best way to roast beets is to put them in my enable pot, with a bit of water in the bottom, and put the lid on and then place the whole thing in the oven. It saves on tin foil!)
When beets cool, remove skin and cut into wedges.
Mix vinegar, oil mustard, salt and pepper to make vinaigrette.
Toss beets with half of the vinaigrette. Place the arugula on a serving platter, arrange beets, almonds, and goat cheese on top. Drizzle with additional vinaigrette. Server warm or room temperature.