Directions

1. For the sour cream sauce, in a small bowl combine sour cream, 1 teaspoon lemon juice, chives, dill and lemon zest; stir well. Cover and refrigerate until serving time.
2. Coat grill rack with nonstick cooking spray. Preheat grill to high (400°F to 450°F). Thread beef cubes, lemon wedges and onion chunks onto 4 to 6 long skewers.?Place skewers in a large, shallow glass dish.
3. In a small bowl whisk together 1/3 cup lemon juice, oil, garlic, and salt and pepper to taste. Pour over skewers, turning to coat. Let stand 5 minutes.
4. Place skewers on grill. Grill, covered, 4 to 6 minutes per side (145°F for medium-rare) or to desired doneness, turning occasionally. Serve with sour cream sauce.