STEP 1 Combine oil, garlic and chilli in a small bowl. Season with salt and pepper. Thread beef onto 8 metal skewers. Brush with chilli mixture. Set aside for 15 minutes.
STEP 2 Meanwhile, preheat a greased char-grill pan or barbecue over medium-heat. Spray corn cobs with oil and char-grill or barbecue, turning occasionally, for 8-10 minutes until lightly charred. Set aside to cool.
STEP 3 Char-grill or barbecue beef skewers for 8-10 minutes (for medium rare) or until cooked to your liking. Transfer to a plate, cover and rest for 5 minutes.
STEP 4 Slice corn kernels from the cobs and place into a large bowl. Add tomatoes, onion, coriander and lime juice. Gently toss to combine.
STEP 5 Serve beef skewers with sweetcorn salad, avocado, extra chopped jalapeno chilli, lime wedges, sour cream and warmed tortillas.