Preheat the oven to 425 F. Line a sheet pan with parchment for easier cleanup.
Wash the potatoes and cut them in half. Toss them with 1 tablespoon of olive oil, a pinch of salt, and a little pepper. Spread them on the pan in a single layer.
Pat the chicken dry with paper towels. This helps the skin get crispy. In a small bowl, whisk together the remaining olive oil, garlic, oregano, thyme, red pepper flakes, lemon zest, lemon juice, salt, and pepper.
Nestle the chicken thighs among the potatoes on the pan. Rub the seasoning mixture over the chicken, making sure the skin gets a nice coating.
Roast in the oven for about 30 to 40 minutes, until the potatoes are tender and the chicken registers 165 F with a thermometer and the skin is golden and crisp.
If you like extra crispness, broil on high for 1 to 2 minutes at the end, watching closely so nothing burns.
Remove from the oven and let rest for a few minutes. Scatter fresh parsley over the top and serve with a squeeze of additional lemon if desired.