01 - Preheat the oven to 425°F.
02 - Arrange fennel wedges on a baking sheet. Drizzle with olive oil, sprinkle with sea salt and black pepper, and toss to coat evenly.
03 - Roast fennel for 20-25 minutes, turning once halfway through, until golden and caramelized at the edges. Let cool slightly.
04 - Meanwhile, prepare oranges and grapefruit by removing all peel and pith, then slicing into rounds or segmenting.
05 - In a small bowl, whisk together extra-virgin olive oil, lemon juice, honey, Dijon mustard, salt, and pepper until emulsified.
06 - On a large serving platter, layer roasted fennel, orange slices, and grapefruit segments.
07 - Drizzle with dressing, then scatter over dill, mint, parsley, and toasted nuts if using.
08 - Serve immediately, or let stand 10 minutes to allow flavors to meld.