In a small bowl whisk together chicken stock and flour. Set aside.

In a bowl combine 1 Tbsp olive oil, lemon zest, 1 lemon juiced, and garlic powder. Add chicken, turning to coat. Let stand for 30 minutes.

Remove chicken from marinade and sprinkle both sides with salt and pepper.

Heat a large skillet over medium-high heat. Spray pan with non-stick spray. Add chicken, and cook for about 5 minutes per side or until done. Remove from pan and cover to keep arm.

Reduce the heat to medium. Swirl remaining 1 Tbsp oil to coat the pan. Add shallot and cook for 2-3 minutes until soft. Add garlic and cook for 30 seconds. Pour in the sherry. Let simmer for 5 minutes, until most of the liquid evaporates.

Stir in the chicken stock mixture. Add artichokes and cook for 1 minute, until the sauce starts to thicken. Stir in remaining lemon juice.

Top with chopped parsley. Serve immediately.