Place the aubergines, herbs and salt in a deep enamelled cast iron pot (you can use stainless steel but the result might be a little different) and cover with the extra virgin olive oil. The quantities I suggested in the ingredient section are approximate, the important thing is to make sure you have enough oil to submerge the vegetables entirely. You can also add garlic here to taste, but I prefer to keep the flavours clean as I tend to season the aubergines when I use them later.
At this point I turn the heat on, let the oil come to a very slow simmer and cover with a lid then turn the heat off.