Prepare the mashed potatoes by boiling quartered Yukon gold potatoes in salted water for 20-25 minutes, then mash with butter, garlic powder, heavy cream, salt, and pepper.

Preheat your oven to 400°F (200°C). Sear chicken thighs in a skillet for about 5-7 minutes skin-side down until golden. Flip and cook for another 1-2 minutes.

Sauté diced onion and fennel in the skillet for 5-7 minutes. Add halved cherry tomatoes, minced garlic, lemon juice, and red pepper flakes and cook for 2-3 minutes.

Pour in water, wine, or stock and scrape the skillet for flavor. Simmer and stir in butter until melted and sauce thickens.

Place chicken thighs on top of vegetables in the skillet, roast in the oven for about 20-25 minutes until the internal temperature reaches 165°F (75°C).

Reheat the mashed potatoes and serve the chicken with the sautéed vegetables and mashed potatoes, garnished with fennel fronds and pepper flakes if desired.