Cut the tomatoes (meaty part only), onions and chili peppers into small pieces. Remove the pits from the avocados and using a spoon, carve out the soft insides from the rind.
Mash the fruit's insides, mix them with the juice of a squeezed lime and add the tomatoes, peppers and onions.
Add the olive oil, salt and chopped coriander. Stir well and serve with nachos.