Combine salad dressing and mustard in small bowl. Place beef Skirt Steak and half of dressing mixture in food-safe plastic bag; turn to coat steak. Close bag securely; marinate in refrigerator 6 to 24 hours, turning occasionally. Cover remaining dressing; refrigerate.
Cook quinoa according to package directions; set aside.
Meanwhile, place squash in 2-quart microwave-safe bowl; cover. Microwave on HIGH 5 minutes. Remove from microwave. Cool; set aside.
Remove steak from marinade; discard marinade. Place steak on rack of broiler pan so surface of beef is 2 to 3 inches from heat. Broil 8 to 12 minutes for medium rare (145°F) to medium (160°F) doneness, turning once. Carve steak diagonally across the grain into thin slices.
Meanwhile, combine greens, squash, apple, feta cheese and remaining dressing mixture; toss to coat. Place salad on plates. Spoon scant 1/2 cup quinoa in center of salad; top with beef slices. Sprinkle with toasted almonds.
Nutrition information per serving: 787 Calories; 180 kcal Calories from fat; 20 g Total Fat; 6 g Saturated Fat; 8 g Monounsaturated Fat; 82 mg Cholesterol; 520 mg Sodium; 41 g Total Carbohydrate; 5.9 g Dietary Fiber; 34 g Protein; 6.4 mg Iron; 5.3 mg NE Niacin; 0.7 mg Vitamin B6; 3.7 mcg Vitamin B12; 5.9 mg Zinc; 18.3 mcg Selenium; 98.1 mg Choline;