Preheat oven to 425º Line a large baking sheet with parchment paper.
Slice beets into sixths. Slice sweet potato into similarly sized wedges. Slice carrots into long juliennes, about 1/4” thick. Peel and thinly slice the shallot.
Use a spice grinder or mortar and pestle to grind the coriander and fennel seeds to a coarse consistency—mostly powder, with some texture of the seed remaining.
Place all sliced veggies on parchment paper in a single layer, mixing to distribute evenly. Drizzle with olive oil, and sprinkle with ground coriander and fennel seeds, ground cumin, sea salt, and black pepper. Toss to coat evenly. Roast for 30-35 minutes, rotating pan and turning over veggies with a spatula halfway through. Remove once all veggies are tender and beginning to brown at the edges.
While they roast, mix yogurt, orange and lemon juice, minced fennel, fennel frond, sprinkle of sea salt, and a drizzle of olive oil in a small bowl. Set aside.
Place chopped hazelnuts on a small baking sheet and place in oven for 2-3 minutes. Remove when they are fragrant and just beginning to turn golden brown.
Distribute roasted veggies to individual bowls, and top with citrus fennel yogurt and roasted hazelnuts.