In a small bowl, combine ½ of the lemon zest and juice with the garlic and rosemary and stir to combine. Place remaining lemon zest in an airtight container and freeze for future use in marinades, soups, or salad dressings. Reserve remaining lemon juice and set aside.

Unroll chicken thighs, if necessary, to expose entire surface area. Season with salt and pepper, if desired.

Place chicken thighs in a large, sealable plastic bag and pour marinade on top. Seal bag and turn several times to ensure chicken is evenly coated. Place bag in the refrigerator to marinade for at least 30 minutes or overnight.

When ready to cook, heat olive oil in a large skillet over medium-high heat. Remove chicken thighs from bag, allowing excess marinade drip off before transferring to another dish. Discard remaining marinade.

Working in batches if necessary, add chicken thighs to hot skillet and cook until browned on each side, approximately 3-4 minutes per side. Transfer thighs to a clean serving platter and set aside.

Add remaining lemon juice and ¼ cup water, if necessary, to hot skillet to deglaze. Gently scrape surface of pan with spatula to remove any browned bits. Bring liquid to a boil and then reduce heat to medium-low.

Return chicken thighs to skillet and simmer for 3-4 minutes or until chicken is cooked through. Season with additional salt and black pepper, to taste. Remove from heat and serve immediately with your choice of sides.