Ceviche

• 1 1/2 lbsea bass fillet · or corvina, halibut or fluke, skinned and pin-boned, bought the same day
• 3/4 cupfresh lime juice · about 8 limes, squeezed within the hour, never bottled
• 1 1/2 tspkosher salt · plus more to taste at the end
• 1 smallred onion · sliced paper thin, rinsed in cold water for 10 minutes
• 1 wholeaji amarillo chile · or a serrano, seeded and finely minced
• 1 clovegarlic · grated on a microplane, a small clove
• 1 inchfresh ginger · grated, optional but it lifts the lime
• 2 tbspcelery · very finely chopped, it goes into the leche de tigre
• 1/2 cupcilantro leaves · roughly torn, stems reserved for the leche de tigre
• 1 smallsweet potato · boiled whole, cooled and cut into rounds, served alongside
• 1/2 cupcancha or toasted corn · for crunch, or leave it out
• 1/4 tspblack pepper · freshly ground

Method

1. 1

   The fish is the recipe, so buy it the day you serve it

   You want a firm, lean, white-fleshed fish that will hold its shape in acid: sea bass, corvina, halibut, fluke, snapper or grouper. It has to smell of the sea and nothing else, and the flesh should spring back when pressed. Tell the counter it is for ceviche and ask what came in that morning. Salmon and tuna work but behave differently, going soft rather than firm, and oily fish such as mackerel turn unpleasantly metallic in lime.

2. 2

   Freezing is a safety step, not a compromise

   Acid firms protein but it does not reliably kill parasites, so the FDA recommendation for fish eaten raw or lightly cured is that it has been frozen to minus 4F for seven days or blast frozen to minus 31F. Most fish sold as sushi grade has been through that, and a good counter will tell you. Previously frozen fish is often the safer choice here rather than the lesser one, and once thawed slowly in the fridge it behaves identically in the bowl.

3. 3

   Everything stays cold, including the bowl

   Put your mixing bowl in the freezer for ten minutes before you start. Keep the fish in the fridge until the moment you cut it, work quickly, and return the cubes to the fridge while you build the leche de tigre. Warm fish in acid goes mushy at the edges while the middle is still raw, which is the texture problem most home ceviche has. This is twenty minutes of prep, and the fish should never be out of refrigeration for more than about ten of them.

4. 4

   Half-inch cubes, cut against the grain

   Trim any dark bloodline, then cut the fillet into cubes of about half an inch, slicing across the muscle fibers rather than along them. Uniformity matters more than size here, because the cure works from the outside in and mixed cube sizes give you some pieces chalky and some raw in the same bowl. A very sharp knife and a single clean stroke per cut, because sawing tears the flesh and it will fall apart in the lime.

5. 5

   Build the leche de tigre first and taste it before the fish goes near it

   Blitz or whisk the lime juice with the grated garlic, ginger, chopped celery, the cilantro stems, the chile and the salt, then strain it. It should taste sharp, salty and slightly hot, and it should be genuinely good to drink on its own. If it is only sour, it needs salt. This is the seasoning of the entire dish and there is no chance to correct it later, because once the fish is in, the clock is running.

6. 6

   Rinse the onion or it bullies everything else

   Slice the red onion as thinly as you can manage, ideally on a mandoline, then leave it in a bowl of cold water for ten minutes and drain it hard. That pulls out the harsh sulphur compounds and leaves the sweetness and the color. Unrinsed raw red onion is the flavour that dominates most bad ceviche and stays on your breath for the rest of the day. Do this while the fish is still in the fridge and it costs no extra time.

7. 7

   Fifteen to twenty minutes, and set an actual timer

   Combine the fish and the leche de tigre in the cold bowl, stir once, and put it back in the fridge. At fifteen minutes the cubes are opaque outside and just translucent at the center, which is the texture you want. At forty minutes they are firm all the way through and starting to go chalky. At two hours they are cotton wool. The old instruction to marinate for several hours comes from a time when nobody trusted the fish, and it is why so much ceviche is dry.

8. 8

   Add the onion, chile and cilantro at the finish, not at the start

   The rinsed onion, the torn cilantro leaves and any extra sliced chile go in during the last minute, off the timer. Everything added earlier gets cured too, loses its snap and turns the same pale color as the fish. Taste one more time for salt, because the fish absorbs a surprising amount of it during the cure and the bowl almost always wants a final pinch just before it goes to the table.

9. 9

   Serve within the hour, and drink what is left in the bowl

   Spoon it into cold bowls with the sweet potato rounds and the toasted corn, and get it to the table immediately, because it keeps curing on the plate. The leftover leche de tigre in the bottom of the bowl is the best part and is traditionally drunk from a small glass. There are no leftovers with ceviche: what is not eaten within an hour should be cooked into a soup or thrown away. It is whole30 compliant exactly as written.