Generously sprinkle your chicken thighs or breasts with salt and black pepper. Let them sit while you prepare your skillet to build rich flavors.

In a large skillet, heat 1 tablespoon of butter over medium-high heat. Once it's hot and bubbly, carefully add the seasoned chicken. Sear for 4-5 minutes on each side until golden brown. Remove the chicken and set aside.

Reduce the skillet heat to medium and add the remaining tablespoon of butter. Toss in the finely chopped onion and sauté for about 5 minutes until it softens and turns golden.

Stir in the minced garlic and cook for another minute, allowing it to become fragrant. Watch closely so the garlic doesn’t burn, which can lead to a bitter taste.

Sprinkle in the all-purpose flour and stir constantly for about 2 minutes to create a roux. The raw flour taste should disappear.

Gradually whisk in 1.5 cups of chicken broth while scraping the skillet’s bottom to incorporate all the delicious browned bits. Bring this mixture to a simmer, allowing it to thicken slightly.

Return the seared chicken to the skillet, covering and simmering on low heat for 15-20 minutes, or until the chicken is cooked through and tender.

While the chicken simmers, boil 2 pounds of peeled and cubed potatoes in salted water for about 15 minutes until fork-tender. Drain the potatoes afterward.

In a large bowl, mash the drained potatoes with 0.5 cup of warmed milk and 1 cup of shredded cheddar cheese. Adjust the consistency to your liking, seasoning with salt and black pepper.

To serve, spoon generous portions of cheesy mashed potatoes onto plates and top them with the tender chicken and rich garlic gravy. Garnish with freshly chopped parsley if desired.