Preheat oven to 375°F (190°C).
Using a mortar and pestle, coarsely crack peppercorns, then mix with salt.
4 Tbsp Whole Black Peppercorns, 2 Tsp Salt
Heat olive oil in a cast-iron skillet over medium-high heat.
Place chicken thighs skin side up in the hot pan. Season generously with the pepper-salt blend. (You don't have to use all the seasoning)
10 Chicken Thighs, 3 Tbsp Oil
Crisp for 3 minutes, flip, season the other side, and sear for another 3 minutes until golden brown.
Transfer skillet to the oven. Bake for 20 minutes, or until chicken reaches an internal temperature of 165°F (74°C).
Remove chicken to a warming plate.
Place skillet back on stovetop. Add onion and garlic to the pan drippings and sauté until softened.
1 Cup Onion, 2 Lrg Cloves Garlic
Deglaze with a splash of chicken broth while cooking onions and garlic, scraping up browned bits.
2 Cups Chicken Stock
Add the rest of the broth and simmer.
Stir together cornstarch and lemon juice to make a slurry.
½ Cup Lemon Juice, 2 Tbsp Cornstarch
Whisk into the broth until sauce thickens.
Return chicken thighs to skillet. Simmer 5–10 minutes, spooning sauce over the chicken.
Remove from heat. Sprinkle with lemon zest and garnish with lemon slices and parsley before serving.
Lemon Zest