Preheat your oven to 425°F.

In a mixing bowl, whisk together the olive oil, lemon zest, lemon juice, minced garlic, rosemary, thyme, salt, and pepper.

Add the chicken thighs to the bowl, ensuring they are thoroughly coated with the marinade. Allow the chicken to sit for at least 30 minutes.

Fill a large pot with water and add the diced potatoes. Bring to a rolling boil and cook until fork-tender, approximately 15-20 minutes.

Drain the potatoes and return them to the pot. Stir in the heavy cream, softened butter, salt, and pepper, then mash until smooth.

Arrange the marinated chicken thighs on a baking tray and roast in the preheated oven for 35-40 minutes, or until the skin is golden brown and crispy, and the internal temperature reaches 165°F.

Plate the roasted chicken thighs next to a serving of creamy garlic potatoes and sprinkle with extra herbs before serving.