Heat oil in a medium fry pan. Add the garlic and half the onion, cook for 2 minutes or until soft. Add mince and taco seasoning, stirring with a wooden spoon for 5 minutes or until browned. Season with salt and pepper.
Place the corn chips into a large baking dish, add the mince mixture and sprinkle over the cheese.
Bake in the oven for 12 minutes or until the cheese is melted and golden.
For the salsa, while the nachos are baking, put the remaining half of finely chopped onion into a bowl and squeeze half the lemon on with a pinch of salt – leave to pickle for 5 minutes
Finely chop the red chilli and add to onions along with tomatoes and coriander - season with salt and add lemon juice to taste