- With the rack in the middle position, preheat the oven to 180 °C (350 °F).
- In a large saucepan or Dutch oven, brown the duck legs, skin side down, over medium heat, in the oil. Season with salt and pepper. Set aside on a plate.
- In the same pan, brown the onions in the duck fat. Season with salt and pepper. Deglaze with the brandy. Add the beer, carrots, and rosemary. Place the duck on the vegetables, skin side up.
- Bake, uncovered, for about 1 hour and 30 minutes or until the meat falls off the bone.