Preheat the oven to 400 degrees F.
On a large baking sheet, toss the bread with 1/4 cup of the olive oil and season generously with salt and pepper. Spread in an even layer and bake for about 12 minutes, until golden and almost crisp. Transfer to a bowl and let cool. Keep the oven on.
While the bread toasts, toss the carrots with 2 tablespoons of the olive oil, and the coriander and cumin seeds. Squeeze the juice of 1 of the oranges and the lemon over the carrots. Season generously with salt and pepper and toss to mix. Spread on two large rimmed baking sheets and roast for about 25 minutes. Let cool.
In a small bowl, whisk together the vinegar, shallot, mustard, honey, and the remaining 6 tablespoons olive oil. Season the vinaigrette with salt and pepper.
In a large serving bowl gently toss the bread, carrots, nuts, tomatoes, the remaining orange, and avocados with the vinaigrette. Add the radicchio and toss to mix. Serve at room temperature.