Preheat the oven to 475 degrees F.
In a roasting pan, lay the onion and leek wedges on the bottom of the pan, drizzle with olive oil and sprinkle with salt and pepper.
Salt and pepper cavity of the room-temperature chicken, insert two onion wedges, 4 cloves of garlic, and one thyme sprig into the cavity.
Melt 4 tablespoons of butter, with about half the thyme leaves and remaining smashed cloves of garlic. Using a pastry brush, brush the melted butter all over the back side of the chicken; place chicken on top of the onions and leeks with breast facing up. Tuck wings under the chicken.
Wrap the kitchen string under the neck end of the chicken and pull the string ends criss-cross under the pointy end of the breast just above the cavity and pull tight (this will puff up the chicken breast). Tie a knot, wrap each end around the closest leg end, and tie tightly so that the legs come together across the cavity. Tie a knot
Brush remaining melted butter over the front and sides of the chicken. Sprinkle salt, pepper, and remaining thyme leaves over the top of the chicken
Place the roasting pan with the prepared chicken in the preheated oven and roast for 25 minutes. Reduce the heat to 400F and roast for an additional 45 minutes, or until the thigh registers an internal temperature of 160 degrees F. on your meat thermometer (juices will run clear when cut with the tip of a knife).
Remove chicken from oven and transfer to a cutting board, cover with foil, and let rest for 20 minutes. If you are going to eat the onions and leeks, place them in the turned off oven to keep warm. Select the best crisped veggies to use on the platter (they will be very crispy and yummy).
Cut chicken into serving pieces, place on the serving platter, and place crispy veggies along the sides. Drizzle pan juices on top of chicken.
Makes 4 servings.
* Choose a chicken weighing around 4 pounds. I prefer organic, free range chickens as I think they taste better. Wash and dry the chicken, place on a plate, and put into the refrigerator, uncovered for 1 to 2 days (this dries out the skin which will give a crisper skin after roasting). Be sure to remove the chicken from the refrigerator at least 2 hours prior to roasting, to bring down to room temperature.
Roast Chicken with Thyme Butter Recipe: https://whatscookingamerica.net/karencalanchini/thymeroastchicken.htm