Pat dry skirt steaks with paper towels or dish cloth. Season generously on both sides with sea salt and black pepper. Refrigerate for at least one hour before cooking.
Simmer shallots, red wine and red wine vinegar on medium heat into a syrup. The shallots will begin to absorb the red wine and turn red in color, approximately 20 minutes. Add 1/2 cup chicken stock and reduce by simmering half way. Reserve until ready.
Heat EVOO in a stainless steal pan on medium to medium-high heat. Do not use non-stick. You will be pan searing the skirt steak and will want it to brown. Skirt steak about 2-inches thick should be seared 6-7 minutes on each side to be cooked until temperature is medium-rare. Skirt steak should not be cooked above medium temperature.
After skirt steak is removed from pan, reduce heat to medium-low and add remaining 1/2 cup of chicken stock to the pan you seared the skirt steak. Deglaze the pan, and pour brown bits and chicken stock into red wine reduction sauce. Reheat and swirl cubed butter into red wine reduction sauce.
Slice skirt steak, pour red wine reduction sauce over top and garnish with parsley.