Trim excess skin or dangling fat off the chicken thighs. Season both sides with salt and place in the fridge, uncovered, for 30 to 60 mins
Stir together olive oil, minced garlic, dried oregano, dried thyme, black pepper, the zest of 1 lemon, and the juice of 1 lemon (approximately 20–30g) in a medium bowl.
Peel and cut potatoes in half, then cut into large wedges. Toss the potato wedges and the salted chicken thighs into the bowl with the marinade to coat thoroughly.
Spray or lightly oil a metal baking pan. Lay the potato wedges in a single layer on the bottom of the pan, then nestle the chicken thighs on top, skin side up. Pour 150g of chicken stock into the pan around the potatoes
Bake uncovered at 350°F/175°C for 75-90 minutes.
Remove the pan when the chicken reaches an internal temperature of 185–190°F (85°C). Rest in the pan for 15-25 minutes.
Transfer the chicken and potatoes to a serving platter and keep warm in a very low oven. Pour 50 g (1/4 c) chicken stock into the roasting pan and scrape up the browned stuff on the bottom and around the sides. Move this liquid to a small pan and whisk in dijon mustard. Reduce for 2-3 minutes over high heat until the sauce is thickened and a drawing a spatula through it leaves a trail. To serve, pour the sauce over the finished greek chicken and potatoes. Top with fresh chopped parsley and a squeeze of lemon juice.