How to Make It
Preheat oven to 400°F. Place a piece of aluminum foil over the hole of the center of a cast-iron Bundt pan. Combine thyme, grated garlic, 1 1/2 teaspoons of the salt, 3/4 teaspoons of the pepper in a small bowl. Rub chicken inside and out with thyme mixture.
Toss together potatoes, carrots, onions, fennel, oil, whole garlic cloves and remaining 1/2 teaspoon each of salt and pepper in Bundt pan.
Place chicken cavity over the foil-lined center of Bundt pan, nestling it into vegetables. Place Bundt pan on a rimmed baking sheet, and roast in preheated oven until chicken is golden, and a thermometer inserted in thickest portion registers 165°F, 1 hour to 1 hour, 15 minutes.