Beta Carotene: Carrots are loaded with this member of the carotenoid family (responsible for all the pretty oranges, yellows and reds we see in fruits and vegetables). Our bodies convert Beta Carotene to vitamin A, which helps promote healthy skin and vision (especially at night). Beta carotene is also an antioxidant: It seeks out free radicals in the body to stabilize them.
Preheat the oven to 350 degrees F. Spread the hazelnuts out on a baking sheet and toast until golden, 8 to 10 minutes. Cool and slightly crush (the bottom of a measuring cup works well).
Add the coriander to a small skillet and swirl over medium heat until toasted, about 2 minutes. Crack the coriander and add to a baking dish along with the hazelnuts, shallots, vinegar, honey, 1/2 teaspoon salt, the cayenne and the juice of 1 orange. Whisk in the olive oil in a slow and steady stream. Set aside.
Fit a medium, shallow pot with a steamer insert and add about an inch of water. Bring to a simmer, add the carrots, cover and steam until just fork-tender, 10 to 12 minutes. Transfer to the baking dish, toss gently and allow the carrots to cool in the vinaigrette at room temperature.
Segment the remaining orange and arrange the carrots on a serving platter, topped with the orange segments. Sprinkle with salt if desired. Serve.