In a small sauce pan, sweat shallot in 1 tsp. butter, add thyme and beef stock and reduce to ¼ cup. Add port wine and reduce to 1/3 cup and remove from heat. Whisk in remaining butter, ½ tbsp. at a time. Grill steaks to desired doneness. Using a pastry or basting brush, coat each steak evenly with the glaze and serve.