Set a rack in the center of the oven and heat the oven to 400°F. Rinse the chicken parts and pat them dry; season generously with salt and pepper. Heat 1 Tbs. of the oil in a 10-inch sauté pan over medium-high heat until very hot. Working in two batches, brown the chicken well on both sides, 3 to 4 min. per side. Transfer the chicken, skin side up, to an 11x14-inch or similar roasting pan and bake until cooked through, about 15 min.
Meanwhile, over medium heat, toast the fennel seeds in a small dry skillet, stirring frequently, until golden and fragrant, 2 to 3 min. Transfer to a small bowl and add the remaining 2 Tbs. olive oil, the breadcrumbs, 1/2 tsp. salt, and 1/8 tsp. pepper.
Remove the chicken from the oven and raise the oven temperature to 500°F. Turn the chicken pieces over and, with a pastry brush, lightly dab the mustard on top. With your hands, press the breadcrumb mixture on top of the mustard. Bake until the crumb crust turns golden, about another 10 min. Transfer the chicken to a serving platter, sprinkle with the parsley, and serve.