Combine lemon zest and 1/2 lemon juice with garlic and rosemary. Combine well.
Season chicken thighs with salt and pepper.
Place chicken thighs in an air tight container. Pour marinade on top. Close and shake to thoroughly combine. Allow to marinate for at least 30 min, or overnight.
Heat olive oil in large skillet over medium-high heat. Can be a dutch oven or a cast iron skillet if available.
Place marinated chicken info hot skillet to sear for about 3-4 min each side. Remove chicken from skillet and set aside.
Add remaining lemon juice and 1/4 cup of water to hot skillet to deglaze. Gently scrape surface of pan to remove any browned bits. Bring to a boil and reduce heat to medium-low.
Place chicken back into skillet to simmer 3-4 minutes or until chicken is cooked through. Remove from heat and serve immediately.