Prepare the roasted fennel according to these directions. Slice it into 1/2-inch wedges. First, I clip off the stalks so that I’m left with the white bulb. I cut it in half vertically and then cut each half into several wedges. To roast the wedges, spread them cut-side-down on a baking sheet with a little space between each one. Toss them with olive oil, salt, and pepper, and roast at 400 degrees for 25-35 minutes, until the wedges are tender and caramelized around the edges.
Make the dressing: In a small bowl, whisk together the olive oil, lemon juice, garlic, and Dijon mustard.
In a medium bowl, toss the sliced fennel with a few drizzles of the dressing. Set aside for 15 minutes so the fennel softens a bit.
Assemble the salad on a platter by arranging half of the sliced fennel, all the roasted fennel, radicchio, and half of the citrus segments. Drizzle with a few spoonfuls of the dressing and sprinkle with salt. Layer the remaining fennel and the remaining citrus onto the salad. Top with the avocado, pine nuts, pecorino, and mint. Drizzle with more dressing, sprinkle with salt and pepper, and serve.