-
1
Pat all three birds dry inside and out with paper towels.
-
2
Butterfly the chicken by cutting along both sides of the backbone and removing it; season cavity with salt and pepper.
-
3
Season the duck cavity; place inside the chicken cavity, legs folded inward; truss chicken legs with kitchen twine.
-
4
Season the turkey cavity with salt, pepper, and half the herbs; place the chicken-duck combination inside the turkey cavity, folding wings under.
-
5
Rub entire turducken with softened butter, season exterior generously with salt, pepper, remaining herbs; place on a sturdy roasting pan, scatter onion around base, pour stock into pan.
-
6
Roast at 160°C for 3–3.5 hours, basting every 30 minutes with pan juices; turducken is done when the thickest thigh (turkey) registers 74°C on an instant-read thermometer.
-
7
Rest the assembled bird uncovered for 25 minutes before carving.
-
8
Carve by cutting through all three birds simultaneously, revealing the distinct layers; serve with pan juices strained and skimmed of fat.