Take it from someone who learned the hard way: tomatillos are very much not green (under-ripe) tomatoes. They’re a completely different product with a different flavor. Tomatillos also have a lot more pectin than tomatoes, which gives this salsa nice body....
This is one of those dishes that’s ubiquitous and still manages to raise the hackles of purists. I would argue that the purity tests around the ragù alla bolognese are unfounded....
This is a salsa in the Mexican, rather than Italian sense. I don’t entirely remember how this name came to be. Perhaps that this is a step up from the most basic salsa it’s possible to make, tossing a few ingredients together in a bowl....
Confusingly, the words for sauce and green are identical in Spanish and Italian. This sauce is the Italian salsa verde. I’ll keep saying this over and over: don’t let the anchovies put you off....
A vinaigrette (as well as the mayonnaise and the aïoli) is an emulsion. That is, a mixture of two liquids that are otherwise difficult to combine. In this case, that’s the vinegar, which is mostly water, with the oil....