Roasted Chicken with Pan Gravy

To prepare chicken: Preheat oven to 450 degrees F. Coat a small, shallow roasting pan with cooking spray.

Let chicken stand at room temperature for 30 minutes. Thoroughly pat dry with paper towels, inside and out. Gently separate the skin from the meat and season under the skin and inside the cavity with salt and pepper. Tie the legs together with kitchen string, mostly closing the cavity opening. Tuck the wing tips under the chickens. Place onion, celery and carrot in the prepared roasting pan. Brush the chicken with oil and set on top of the vegetables, about 2 inches apart.

Roast in the center of the oven for 40 minutes. Rotate the pan 180 degrees . Continue roasting until an instant-read thermometer inserted into the thickest part of the thigh, without touching bone, registers at least 165 degrees F, 20 to 30 minutes more.

Tilt the chicken so the juice from the cavity runs into the pan. Reserve the juice and vegetables for making the gravy. Transfer the chicken to a clean cutting board. Let rest 15 minutes.

Meanwhile, prepare pan gravy: Set a fine-mesh sieve over a 4-cup measuring cup (or similar-size bowl). Scrape the reserved pan juices and roasted vegetables into the sieve; press on the vegetables to extract as much liquid as possible. (Discard the vegetables.) Transfer the juices to the freezer for about 10 minutes.

Spoon the layer of fat off the top of the pan juices, then add enough broth (or stock) to the defatted juices to make 1 1/2 cups. Pour the mixture into a small saucepan and bring to a boil. Reduce heat to medium-high and boil until reduced to about 1 1/4 cups, 5 to 7 minutes.

Whisk cornstarch and water in a small bowl; whisk the mixture into the boiling liquid. Cook, whisking, until thickened, 1 minute. Remove from heat and stir in butter.

Remove the string from the chicken and carve. Serve the chicken with the gravy.