A Yerba Mate Crust for Steak
Argentina’s national drink, pressed onto beef and put over fire. Nobody else is doing this.
Yerba mate is drunk by nearly everyone in Argentina, every day, out of a gourd through a metal straw. It has essentially never been treated as a cooking ingredient. That was the opening, and there turns out to be a good reason to walk through it: toasted mate on beef tastes like smoke, tea, and something faintly bitter in the way good char is bitter, and it forms a crust unlike anything else you can put on a steak.
Toast it first, and watch it
Raw yerba mate on a steak tastes like a lawn. Toasted mate tastes like toast. The whole recipe turns on this step.
Dry pan, medium heat, mate in a single layer. Three to four minutes, moving it constantly. It goes from green-grey to brown, and the smell shifts from hay to something closer to toasted grain and tobacco.
The window is about ninety seconds wide. Under-toasted is grassy and unpleasant. Over-toasted goes acrid in a way no amount of salt or fat will fix, and there is no rescuing it — throw it out and start again. Take it off the moment it smells like toast, and tip it straight out of the pan, because the pan will keep going.
Yerba & Humo is already toasted to that point and blended with smoked salt and pepper, which removes the only difficult part of this.
The crust
A thick steak — an inch and a half at least, ribeye or strip. Thin steaks do not work; the crust needs time to form and a thin steak is done before it does.
Dry the surface properly. A tablespoon of the toasted mix pressed onto both faces, firmly, thirty minutes ahead. Let it sit at room temperature in that time.
Very hot pan or very hot grill. The mate will darken further and smell strong — that is the crust forming, not burning. Do not move the steak around. Sear, flip once, finish to temperature, rest ten minutes.
Salt after, if it needs it. Mate carries a bitterness that reads as under-salted at first and resolves as it rests.
The strange ones that work
Toasted mate is closer to tea than to a spice, and it behaves like one.
Steep a tablespoon in warm cream for twenty minutes, strain, and make vanilla ice cream with it. Grate a little over dark chocolate. Put a spoonful in the sugar for an old fashioned and stir it out after a minute. Rub it on salmon, which sounds wrong and is the second-best use after beef.
One thing to know
Mate has caffeine — roughly a cup of coffee’s worth per traditional serving. A tablespoon on a steak is not much, and most of it stays in the crust rather than in you. But if you are cooking for somebody who cannot have caffeine at eight in the evening, say so before you serve it.