Begin by generously seasoning both sides of the chicken breasts or thighs with salt and black pepper. Let sit for about 10 minutes.

In a large skillet, heat 2 tablespoons of olive oil over medium-high heat. Sear chicken for 5-7 minutes on each side until golden and cooked through.

Reduce heat to medium, melt 2 tablespoons of butter, then add minced garlic and sauté for 30-60 seconds until fragrant.

Sprinkle 2 tablespoons of all-purpose flour over garlic, stirring continuously for 1-2 minutes to create a roux.

Gradually whisk in 2 cups of chicken broth, cooking until thickened slightly, about 3-5 minutes. Optionally stir in 1/4 cup of heavy cream.

Boil cubed Yukon Gold potatoes in salted water for 12-15 minutes until fork-tender. Drain well.

In a mixing bowl, combine drained potatoes with 2 tablespoons of butter, 1/4 cup of milk, and 1 cup of cheddar cheese. Mash until smooth.

Serve by placing cheesy mashed potatoes on plates, topping with sliced chicken, then spooning gravy over the top. Garnish if desired.