Chinese red oil (红油, or the equivalent, Japanese raiyu らい油) is a critical ingredient in any number of Sichuanese dishes, including sesame noodles, or husband-wife boiled beef slices. It’s great with black vinegar, as a dumpling sauce. And it’s versatile enough to use with other kinds of cuisine as a spicy condiment. It’s a beautiful ruby red color, and has a fantastic toasty aroma. You can buy it, if you like, but it’s ridiculously simple to make. It might look intimidatingly fiery, but the flavour is a mellow, slow heat (even if you use spicy chili flakes).
— Brad, Ulli