Season your chicken thighs or breasts generously with salt and pepper. In a large skillet, heat olive oil over medium-high heat. Add the chicken and cook for about 5-7 minutes per side until golden brown and reaches an internal temperature of 165°F. Keep warm.

In the same skillet, reduce heat to medium and add butter. Once melted, add minced garlic and sauté until fragrant. Sprinkle in all-purpose flour to create a roux. Gradually whisk in chicken broth and simmer until thickened. Stir in cream if desired.

Peel and cube potatoes. Place in a pot, cover with salted water, and boil for 12-15 minutes until tender. Drain and return to pot to steam off excess moisture.

Add butter, milk, and cheddar cheese to the drained potatoes. Mash until smooth and creamy, adjusting milk for consistency. Season with salt and pepper.

Spoon cheesy mashed potatoes onto plates, slice the warm chicken over them, and ladle garlic gravy on top. Garnish with parsley or chives.