In a large bowl, combine smoked paprika, sweet paprika, dried parsley, dried thyme, garlic powder, minced garlic, lemon juice, olive oil, salt, and black pepper. Add the chicken thighs and coat well, making sure the seasoning is evenly distributed. Cover and marinate in the refrigerator.
Preheat your oven to 400°F.
In a separate bowl, toss the small potato chunks with olive oil, salt, garlic powder, smoked paprika, and dried thyme until evenly coated. Spread the potatoes in a single layer in a large baking dish or sheet pan.
Place the marinated chicken thighs on top of the potatoes, skin-side down first so they absorb the flavors while baking.
Bake uncovered for 25 minutes, then flip the chicken so the skin is facing up. Continue baking for another 20–25 minutes, until the chicken is golden and fully cooked.If your potatoes need more time or you prefer them softer, you can loosely cover the pan with foil and bake for an extra 10–15 minutes. For extra crispy skin and roasted potatoes, broil for 3–5 minutes at the end. Watch closely to avoid burning.
Once the potatoes are fork-tender, take the pan out of the oven and let the chicken rest for 5 minutes. Finish with fresh parsley and a squeeze of lemon juice right before serving.