What's the magic? Perhaps that there's not much magic at all. Most salsa powder—Tajin included—is made with nothing more than chiles, salt, lime, and an anti-caking agent. Tajin's chile is roasted and rich but bright, fiery but with an ephemeral burn. The salt's abundant, and thus you should sprinkle with care, but it doesn't overwhelm. And the dehydrated lime juice really does evoke fresh, aromatic citrus—not just crystalized citric acid—which makes for a concentrated hit of twang that's had time to meld with the chile and won't add liquid to whatever you're seasoning.