1. Adjust oven rack to lowest position and heat oven to 250 degrees. Pat chicken dry with paper towels and season with salt and pepper. Heat oil in large Dutch oven over medium heat until just smoking. Add chicken breast-side down; scatter onion, celery, garlic, bay leaf, and rosemary (if using) around chicken. Cook until breast is lightly browned, about 5 minutes. Using a wooden spoon inserted into cavity of bird, flip chicken breast-side up and cook until chicken and vegetables are well browned, 6 to 8 minutes. Remove Dutch oven from heat; place large sheet of foil over pot and cover tightly with lid. Transfer pot to oven and cook until instant-read thermometer registers 160 degrees when inserted in thickest part of breast and 175 degrees in thickest part of thigh, 80 to 110 minutes.

2. Transfer chicken to carving board, tent with foil, and rest 20 minutes. Meanwhile, strain chicken juices from pot through fine-mesh strainer into fat separator, pressing on solids to extract liquid; discard solids (you should have about 3/4 cup juices). Allow liquid to settle 5 minutes, then pour into saucepan and set over low heat. Carve chicken, adding any accumulated juices to saucepan. Stir lemon juice into jus to taste. Serve chicken, passing jus at table.

STEP BY STEP: Moist Chicken with Concentrated Flavor

1. Brown: Sear chicken on both sides to enhance flavor.

2. Seal: Cover pot with foil before adding lid to trap chicken juices inside.

3. Slow Cook: Cook chicken at 250 degrees for 80 to 110 minutes.

4. Rest: Transfer chicken to carving board to rest so juices can redistribute.

STEP BY STEP: Dry Cooking versus Braising

French Chicken in a Pot shares some similarities with braised chicken-both are cooked in covered pots in low-temperature ovens to yield tender, flavorful meat. Unlike braising, however, where lots of liquid is added to the pot, our chicken is placed in a dry pot and left to cook in nothing more than the essence of its own juices.

DRY ENVIRONMENT: In a dry pot with no added liquid, juices that come out of the chicken go right back into it, undiluted by other flavors.

WET ENVIRONMENT: The wet environment of a braise creates an ongoing exchange between the flavors of the chicken as well as other ingredients, such as wine, broth, and vegetables.