Roast Chicken With Fingerling Potatoes, Leeks, And Bacon

Ingredients

• 1 3-1/2- to 4-lb. whole chicken
• kosher salt and freshly ground black pepper
• 2 tbs. finely chopped fresh parsley, plus 10 small sprigs
• 4 fresh or dried bay leaves
• 1 tbs. finely chopped fresh thyme, plus 4 sprigs
• 4 large leeks, white and light-green parts halved lengthwise, then sliced crosswise into 3/8-inch pieces (about 4 cups) and rinsed; dark-green parts from 1 leek rinsed and reserved
• 3 strips thick-cut bacon, cut crosswise 3/8-inch thick
• 1 tbs. olive oil
• 2 large cloves garlic, thinly sliced
• 1-1/2 lb. large fingerling potatoes, cut crosswise into 1/8-inch-thick rounds
• 1-1/2 cups lower-salt chicken broth
• 2 tbs. unsalted butter, softened