In small bowl, blend oil, 1 Tsp. orange peel, vinegar, sugar, and 1/4 Tsp. pepper. Use half to toss with red beets, and remainder to toss with golden beets, doing separately.
In medium bowl, mash cheese with back of spoon, gradually adding cream until smooth. Stir in remaining 2 Tsp. orange peel, remaining 1/4 Tsp. pepper, and chopped walnuts.
In six (6-ounce) straight-sided glasses, make a layer of mixed beets (red and golden). Layer with the St. Agur and cream. Add a final layer of the mixed beets and top with the cheese mousse. Garnish with arugula and walnut halves. Serve immediately or chill for up to 2 hours.
TIP: Using the two colors of beets makes for a prettier verrine – but be sure to put the red beets on the bottom so they don’t “bleed” onto the golden beets. It will still be lovely if only red beets are available – just use 4 cups.
TIP: To roast beets, wash and trim but do not peel. Wrap in foil and place on baking sheet. Bake at 400°F for 1 hour for medium beets. Cool in foil, then peel.
TIP: This dish can be paired with a Tempranillo, Shiraz or Amarone wine.