Preheat your oven to 400°F (200°C).
In a large bowl, whisk together the olive oil, lemon juice, minced garlic, oregano, salt, black pepper, paprika, and red pepper flakes (if using).
Add the chicken thighs to the bowl and coat them well with the marinade. Let them marinate for at least 15 minutes (or up to 2 hours in the refrigerator for more flavor).
In a large baking dish, arrange the halved baby potatoes. Drizzle with a little olive oil and season with salt and pepper. Toss to coat.
Place the marinated chicken thighs on top of the potatoes in the baking dish.
Pour any remaining marinade over the chicken and potatoes.
Cover the baking dish with aluminum foil and bake in the preheated oven for 30 minutes.
Remove the foil and bake for an additional 15-20 minutes, or until the chicken is cooked through (internal temperature should reach 165°F) and the potatoes are tender.
Garnish with fresh parsley before serving.