1. Heat a grill or grill pan to medium-high. Clean and lightly oil hot grill. In a small bowl, combine oil, cumin, and coriander; season with salt and pepper.

2. Alternately thread steak, bell pepper, onion, and mushrooms onto ten 8-inch skewers. Brush with oil mixture and grill until steak is medium-rare and vegetables are lightly charred, 6 to 8 minutes, turning occasionally. Refrigerate 4 kebabs, up to 3 days, for later use. Serve remaining kebabs with lime wedges.