Marinade & Dressing:
Combine marinade and dressing ingredients in small bowl. Place beef steaks and 1/4 cup marinade in food-safe plastic bag; turn steaks to coat. Close bag securely and marinate in refrigerator 15 minutes to 2 hours, turning occasionally. Cover and refrigerate remaining marinade for dressing.
Remove steaks from marinade; discard marinade. Place steaks and bell peppers on grid over medium, ash-covered coals. Grill steaks, covered, 8 to 11 minutes (over medium heat on preheated gas grill, cooking times remain the same) for medium rare (145°F) to medium (160°F) doneness, turning occasionally. Grill peppers, covered, 7 to 10 minutes or until tender, turning occasionally. A few minutes before steaks are done, place bread slices on grid. Grill until lightly toasted, turning once. Cut 1 end off garlic clove; rub cut end evenly over both sides of toasted bread.
Carve steak into thin slices; season with salt and black pepper, as desired. Dice bell peppers. Place 1 bread slice upright in each of 6 (1-cup) martini glasses or straight-sided glasses. Layer with equal amounts of spinach, peppers, steak, olives, chopped cilantro and reserved dressing. Top with cheese shavings. Garnish with cilantro sprigs, if desired.
Nutrition information per serving: 184 Calories; 72 kcal Calories from fat; 8 g Total Fat; 2 g Saturated Fat; 2 g Monounsaturated Fat; 46 mg Cholesterol; 413 mg Sodium; 1 g Total Carbohydrate; 1.5 g Dietary Fiber; 17 g Protein; 2.5 mg Iron; 3.4 mg Niacin; 0.5 mg Vitamin B6; 2.8 mcg Vitamin B12; 4.2 mg Zinc; 23.8 mcg Selenium;