1. Prepare grill.
2. Coat a large nonstick skillet with cooking spray; add oil. Place over medium-high heat until hot. Add bell pepper strips, zucchini, and onion; cook 5 minutes, stirring often. Add 1/2 cup broth and thyme. Cover, reduce heat, and simmer 5 minutes.
3. Combine 1/2 cup broth and flour, stirring well with a whisk. Add to vegetable mixture, stirring well. Cook, stirring constantly, until slightly thickened and bubbly.
4. Rub steaks with garlic halves; sprinkle with 1/2 teaspoon black pepper. Place steaks on grill rack coated with cooking spray; grill, covered, 4 minutes on each side or until desired degree of doneness. Spoon vegetables evenly onto individual serving plates; arrange steaks over vegetables.
carbo rating: 8