1. Prepare Sauce. Place tomatoes on grid over medium-high coals. Grill, uncovered, 9-11 min. or until skins are completely blackened, turning frequently. Remove and discard skins from tomatoes. Finely chop tomatoes; place in medium bowl. Add remaining sauce ingredients; season with salt, as desired. Set aside. 2. Cut beef steak into 8 equal pieces. Combine Seasoning ingredients in large bowl. Add beef; toss to coat. Soak four 6-in. bamboo skewers in water 10 min.; drain. Thread 2 beef pieces onto each skewer, leaving small space between pieces. 3. Place skewers on grid over medium, ash-covered coals. Grill, covered, 10-14 min. (over medium heat on preheated gas grill, covered, 9-13 min.) for medium rare (145°F) to medium (160°F) doneness, turning occasionally. 4. Meanwhile, remove and finely chop Swiss chard stems and ribs. Thinly slice chard leaves. Heat oil in large skillet over medium heat until hot. Add onion; cook and stir 4-5 min. or until tender. Add chard stems and leaves in batches, if necessary; cook and stir about 2 min. or until leaves are wilted. Add garlic; cook and stir about 20 sec. Add water; cover and cook 3-5 min. or until stems are tender. Season with salt. 5. Combine orzo with chard mixture; divide among 4 bowls. Top each with 1 beef skewer; spoon some sauce on top. Garnish with pine nuts, if desired. Serve with remaining sauce.