Ingredients

• 1 3/4 pounds beef tenderloin roast, trimmed
• 2 tablespoons soy sauce
• 2 tablespoons fresh lime juice
• 2 teaspoons kosher salt
• 1 teaspoon ground cumin
• 6 (1/4-inch-thick) rounds of red onion (cut from 1 large)
• 2 teaspoons olive oil
• 3 medium zucchini (1 pound), sliced 1/4 inch thick lengthwise
• Special equipment: 6 (8-inch) bamboo skewers

Instructions

1. Soak skewers in water while marinating beef.
2. Cut beef into 24 (1-inch) cubes. Stir together soy sauce, lime juice, salt, and cumin in a bowl and add beef, tossing to coat well. Marinate beef, covered, at room temperature 1 hour.
3. Prepare grill for cooking.
4. After beef has been marinating 45 minutes, lightly brush onion rounds with oil and season with salt and pepper. Grill onion on a well-oiled rack set 5 to 6 inches over glowing coals, carefully turning once with a metal spatula, until lightly charred and tender, 3 to 4 minutes on each side. Transfer to a platter and keep warm.
5. Arrange zucchini on grill and grill until lightly charred and just tender, about 1 minute on each side. Transfer to platter and season with salt.
6. Pat beef dry with paper towels and toss with remaining oil. (Discard marinade.) Thread 4 pieces beef onto each skewer and grill, turning occasionally, until charred, about 5 minutes total for medium-rare.
7. Serve kebabs with onion and zucchini.