Walkaway Roast Chicken with Onions and Potato

2 tablespoons olive oil, divided use
2 tablespoons Dijon mustard
1 teaspoon dried thyme
1 teaspoon dried rosemary
Kosher salt and freshly ground pepper
1 lemon cut in half
1 whole roasting chicken, 3-3 1/2 pounds, rinsed inside and out and patted dry
1 large red onion, cut into thick rounds
4 medium red potatoes, washed but not peeled, sliced in half
1/2 cup chicken broth or water

Heat oven to 375 degrees. In a small bowl, combine 1 tablespoon olive oil, mustard, thyme and rosemary and season with a little salt and pepper. Squeeze one half the lemon into this mixture; squeeze other half into a small bowl. Reserve juice as well as squeezed halves. Rub mustard and herb mixture over chicken and inside its cavity. Put squeezed lemon halves in cavity.

Place onion and potatoes in bottom of a roasting pan and toss with remaining olive oil and some salt and pepper. Make room for chicken in pan and put it in breast side up. Cook until juices run clear when thigh is pricked, about 1 1/4 hours; a meat thermometer inserted into thigh should register 165-170 degrees.

Transfer the vegetables to a serving platter. Pour juices from inside the chicken's cavity into the roasting pan and transfer chicken to a cutting board to rest.

Skim fat from juices in the roasting pan. Set pan over medium-high heat. Add reserved lemon juice and chicken broth or water. Bring to a boil, stirring with a wooden spoon to scrape up the flavorful browned bits stuck to the pan. Carve the chicken or cut it into pieces and serve with the potatoes, onions and some of the pan juices poured over all.

Serves 4.

`Bistro Cooking at Home,'' by Gordon Hamersley