Heat a teaspoon of the oil in a frying pan and add the garlic cloves whole. Fry them for a few minutes without allowing them to burn, just brown slightly.
Add the chilli flakes for the final 30 seconds to toast them, then pour in the rest of the oil, season with salt and turn off the heat.
Once the chilli garlic oil is completely cool, pour it through a sieve into a sterilised, airtight container or bottle and use it whenever you need.