Take a small glass bottle, big enough to contain about 450 ml (1 7/8 cups) olive oil. Prepare the chilli in the quantity described.
Put the chilli into the bottle, forming two layers as shown in the picture.
Fill the bottle with olive oil until nearly the top. Leave about 5 cm (approx. 2") between the oil and the cork.
When the bottle is closed, shake it. Now, put the bottle in a dry, cool and dark place. Once a week give the bottle a shake and after a few weeks, the oil will change to slighlty reddish colour. It could take two or three months to achieve the desirable hotness. Unless you finish the bottle in a month, because you eat pizza every day, the oil can be kept in the bottle for several months (I usually keep it for 8-10 months).