Pierce potatoes with a fork, and arrange on paper towels. Microwave on high 8 minutes, turning potatoes over after 4 minutes. Cook 3/4 cup broccoli 3 minutes in a medium skillet in boiling salted water; drain. Heat oil in skillet. Sauté broccoli, 1 teaspoon garlic, and a pinch of red pepper 1 minute. Cut a slit lengthwise through each potato; push ends inward to form a pocket. Crumble 1 tablespoon feta into each pocket. Fill each pocket with broccoli mixture and 2 teaspoons feta.