Preheat oven to 350ºF.
Stuff the chicken with 1 bulb of fennel, trimmed of stalks and halved, and the herb bundle. Combine butter with poultry seasoning, granulated onion and garlic, and fennel seed. Slather over skin and season liberally with salt and pepper.
Slice remaining fennel bulb and trim and cut stalks into 4-6 inch pieces. Arrange in a roasting pan and combine with leeks, lemon slices, garlic and potatoes. Drizzle liberally with EVOO and season liberally with salt and pepper. Set chicken on top and roast 1 hour. Douse with wine and roast 20-30 minutes more until juices run clear.
Cut chicken into pieces, serve with pan juice and roasted fennel, leeks and potato alongside. Sprinkle with additional fresh herbs for garnish.