Preheat your oven to 375°F (190°C) and position a rack in the middle of the oven.
Create the marinade by whisking together olive oil, lemon juice, lemon zest, dried oregano, minced garlic, Dijon mustard, salt, and pepper in a large bowl until well combined.
Pat the chicken pieces dry with paper towels—this ensures the marinade adheres better and helps the skin crisp up during roasting.
Add the chicken and potatoes to the marinade and toss thoroughly, making sure everything is well-coated. Let it marinate for at least 15 minutes (or up to 4 hours in the refrigerator for more flavor penetration).
Transfer everything to a large roasting pan, arranging the chicken skin-side up and distributing the potatoes around the chicken pieces.
Pour the chicken broth into the bottom of the pan (not over the chicken) to prevent the potatoes from sticking and to create steam for more tender meat.
Roast uncovered for 45 minutes, then increase the temperature to 425°F (220°C) and continue roasting for 15 more minutes until the chicken skin is deeply golden and crispy, and the potatoes are tender when pierced with a fork.
Check that chicken has reached 165°F (74°C) at the thickest part using a meat thermometer to ensure it’s safely cooked through.
Allow the dish to rest for 5-10 minutes before serving, which gives the juices time to redistribute throughout the meat.
Garnish with fresh herbs and feta cheese if desired, and serve directly from the roasting pan for a rustic presentation.