First put a small amount of both the diced onion and tomatoes to one side for your guacamole, approx. a tbsp of each.
Pre-heat your BBQ for 2-4 minutes on a medium heat with the Chef Pan in place, Paella Pan or a frying pan over the pot stand and fry the onion and pepper with a drizzle of oil for a few minutes until softened, then add the tomatoes and fry for a further 3-4 minutes.
Add the sweetcorn and Mexican seasoning, stir well and cook for another minute before adding the tortilla chips and cheese. Turn the heat down to low and cook with the lid on for around 10 minutes, until the cheese has melted.
In the meantime, make the guacamole by mashing the avocado and mixing with the garlic, reserved tomato and onion, juice from the lime and then season with salt and pepper. Serve the nachos piled high with dollops of the guacamole, sour cream and the chilli sauce or salsa.