Combine 2 tsp olive oil with ground coriander, chilli, cumin, oregano and garlic in a bowl.
Add chicken and marinate for 20 minutes. On high, BBQ grill chicken then season with salt and pepper and 1/2 lime juice. Chop into pieces.
BBQ corn until partially charred. Remove and cut kernels into a bowl, mixing in tomato, onion and coriander leaves. Season with salt, pepper and olive oil.
Separately combine aioli with remaining lime juice.
Layer each bread roll with avocado, rocket, chicken, corn salsa and lime aioli then serve.