Roast Chicken with Potatoes and Olives

Name: Roast Chicken with Potatoes and Olives
Cuisine: Mediterranean
Ingredients: 1 bay leaf, crushed; 1 teaspoon fennel seeds; ½ teaspoon crushed red pepper flakes; plus more for serving (optional); 1½ pound fingerling potatoes, halved; ½ cup pitted Kalamata olives; 4 tablespoons olive oil, divided; Kosher salt and freshly ground black pepper; 4 chicken legs (thigh and drumstick; about 3 lb.); ½ cup fresh flat-leaf parsley leaves with tender stems; 1 teaspoon finely grated lemon zest; A spice mill