Grilled beef skewers get even better with a robust marinade

By America’S Test Kitchen The Associated Press

Well-marbled steak tips, with their beefy flavour and tender texture, proved the best choice for our grilled beef kebabs.
We created a robust marinade using several key elements: Beef broth and tomato paste added rich, umami tones, salt helped brine the meat and keep it moist, a bit of sugar helped with caramelization, and rosemary and lemon zest added bright aromas. (For a spicy North African variation, we used cilantro, paprika, cumin, and cayenne.)
We cut the meat into large pieces and packed it tightly onto the skewers to help keep it moist and tender while grilling and also patted it dry to help prevent steaming. We paired our beef with a trio of firm and flavourful vegetables that came into their own when grilled: peppers, red onions, and zucchini.
If you can’t find sirloin steak tips, sometimes labeled “flap meat,” substitute 2 pounds of blade steak (if using, cut each steak in half to remove the gristle). You will need six 12-inch metal skewers for this recipe. If you have long, thin pieces of meat, roll or fold them into approximate 2-inch cubes before skewering.
Servings: 4-6
Start to finish: 1 hour and 15 minutes, plus 1 hour to marinate
1 onion, chopped
1/3 cup beef broth
1/3 cup extra-virgin olive oil
3 tablespoons tomato paste
6 garlic cloves, chopped
2 tablespoons chopped fresh rosemary
2 teaspoons grated lemon zest
2 teaspoons salt
1 1/2 teaspoons sugar
3/4 teaspoon pepper
Beef and Vegetables
1 1/2 pounds sirloin steak tips, trimmed and cut into 2-inch pieces
2 zucchini or yellow summer squash, halved lengthwise and sliced 1 inch thick
2 red or green bell peppers, stemmed, seeded, and cut into 1 1/2-inch pieces
2 red onions, cut into 1-inch pieces, 3 layers thick
For the marinade process all ingredients in blender until smooth, about 45 seconds, scraping down sides of blender jar as needed. Transfer 3/4 cup marinade to large bowl and set aside.
For the beef and vegetables place remaining marinade and beef in 1-gallon zipper-lock bag and toss to coat. Press out as much air as possible and seal bag. Refrigerate for at least 1 hour or up to 2 hours, flipping bag every 30 minutes.
Add zucchini, bell peppers, and onions to bowl with reserved marinade and toss to coat. Cover and let sit at room temperature for at least 30 minutes.
Remove beef from bag and pat dry with paper towels. Thread beef tightly onto two 12-inch metal skewers. In alternating pattern of zucchini, bell pepper, and onion, thread vegetables onto four 12-inch metal skewers.
— For a charcoal grill: Open bottom vent completely. Light large chimney starter mounded with charcoal briquettes (7 quarts). When top coals are partially covered with ash, pour evenly over centre of grill, leaving 2-inch gap between grill wall and charcoal. Set cooking grate in place, cover, and open lid vent completely. Heat grill until hot, about 5 minutes.
— For a gas grill: Turn all burners to high, cover, and heat grill until hot, about 15 minutes. Leave primary burner on high and turn other burner(s) to medium-low.
Clean and oil cooking grate. Place beef skewers on grill (directly over coals if using charcoal or over hotter side of grill if using gas). Place vegetable skewers on grill (near edge of coals but still over coals if using charcoal or on cooler side of grill if using gas). Cook (covered if using gas), turning skewers every 3 to 4 minutes, until beef is well browned and registers 120 F to 125 F (for medium-rare), 12 to 16 minutes. Transfer beef skewers to serving platter, tent loosely with aluminum foil, and let rest while finishing vegetables.
Continue to cook vegetable skewers until tender and lightly charred, about 5 minutes; transfer to platter. Using tongs, slide beef and vegetables off skewers onto platter. Serve.