In a medium-sized bowl, mix together cumin, chili powder, garlic, lime juice, olive oil, salt and pepper. Add shrimp to mixture and stir until coated.
Skewer four shrimp on each skewer, and cook for three minutes on each side until shrimp are cooked through and pink.
In another medium bowl, mix together red onion, avocado, tomato and cilantro, and divide among eight tortillas. Top each with four grilled shrimp and fold over. Place two tacos on each of four plates.
Recipe Notes
Per serving: 365 calories, 16 g protein, 17 g fat (3 g saturated fat), 39 g carbohydrates, 6 g fibre, 73 mg cholesterol, 491 mg sodium