Preheat oven to 425°F. Quarter each carrot lengthwise, and cut each length crosswise into 2-inch pieces. Cut fennel in half lengthwise, and cut each half into 4 - 5 wedges.

Place carrot and fennel in a medium bowl, and drizzle with 2 tablespoons extra-virgin olive oil. Sprinkle over 3/4 of the lightly crushed cumin, coriander and fennel seeds. Season with 2 pinches of kosher salt, then toss to coat and even distribute the spices. Transfer carrots and fennel from the bowl to rimmed baking sheet, and sprinkle with remaining crushed spices, another small pinch of salt, and a pinch of cayenne pepper. Place the baking sheet in the oven, and cook until carrots and fennel are tender and caramelized (20 - 25 minutes), tossing a few times to ensure even browning. Let the carrots and fennel cool completely before adding to the salad.

To make the salad dressing, finely grate the zest of 1 blood orange into a small bowl. Add garlic, lemon juice, 2 tablespoons extra-virgin olive oil, and a pinch of kosher salt, whisking to combine. Season to taste with additional kosher salt.

Next, supreme (segment) the blood oranges. To supreme a blood orange, cut off the top and bottom just until the pulp is exposed. Stand the blood orange up on one of the flat ends. Working from top to bottom, cut away the the peel and pith, following the curve of the fruit. Slice out each orange segment by cutting in towards the center of the fruit along the connective membranes. The segment should fall out on its own, but you can use your knife to help if needed. Repeat with remaining 3 oranges.

To assemble the salad, add carrots, fennel, arugula and black olives to a serving bowl. Gently toss in salad dressing. Taste, then add more kosher salt and lemon juice if needed. Scatter blood orange segments and fennel fronds over top.