Pai Huang Gua (Smashed Cucumber Salad)

Variations

• Why smash it. Knife skills describes a blunt blade like this: "A dull blade does not cut, it crushes. Tomatoes turn to pulp, onion cells rupture and release more of the sharp compounds." In the guide that is damage to avoid. This dish makes it the point. Where a knife passes it leaves a smooth plane and dressing runs off it; a smashed face is torn along the cell walls into ridges and hollows, with much more surface and the inside opened up. Same cucumber, same dressing, completely different result.
• The uneven pieces are deliberate too. The same guide's "uniform size is a cooking decision, not a cosmetic one" is about things that cook — everything in one pot for one length of time. Nothing here is cooked, so that constraint does not apply, and a mixture of thick and thin pieces is what gives it something to chew.
• The garlic is the same idea. Blooming spices says garlic is "three different ingredients depending on heat" — sweet gently, nutty browned, bitter burnt. That is the heat axis. There is no heat at all in this dish; there is a cutting axis instead. Sliced, chopped and crushed garlic from one clove are three different strengths, because the more cells you break the more allicin gets made. And allicin peaks at around ten minutes and then declines, so chopping the garlic while the cucumber salts is arithmetic rather than merely an order of work.
• Pour the salt water off and do not rinse. Salt pulls water out of the cells, as salt and seasoning explains. What matters here is what happens next: leave that water in and the dressing thins into a puddle in the dish; rinse it away and the seasoning that got into the cucumber goes with it.
• Tzatziki runs in exactly the opposite direction. There the cucumber is grated and wrung bone dry so it will not slacken the yoghurt. Here it is opened up so that dressing can get in. One dish takes the water out; the other puts flavour into the space the water left.
• Nor is it oi sobagi. That one is scored, stuffed and fermented for days. This is twenty minutes end to end, and leaving it to sit is how you ruin it.
• Som tam uses a mortar but pounds something else. There the garlic, chillies, beans and tomatoes are pounded to build the dressing, while the papaya is shredded and only turned through it. Here the main ingredient itself is what gets broken. Same action, different target.
• In Greek salad, shopska salad and fattoush the cucumber is one diced component among several. Here the cucumber is the whole dish.
• The variety matters more than you would think. Only a thin-skinned cucumber cracks properly. A thick waxed supermarket one just bends under the blade, so if that is all there is, peel it in stripes before you start.
• Regional. The Sichuan version is loud with chilli oil, Sichuan pepper, roasted peanuts and dried chillies; the northern one is plainer, mostly garlic and vinegar. The photograph is closer to the Sichuan side.

Tips

• Several gentle blows, not one hard one. Hit it once and the middle is pulp while both ends are intact. Lay the flat of the blade on the cucumber and press down with your palm, moving along it from end to end.
• Do it inside a bag and nothing sprays. The kitchen stays clean and the force is easier to judge.
• If the cucumber is seedy, halve it and scrape the seeds out with a spoon. That part is water without crunch.
• Use black vinegar. The malty sweetness of Chinkiang is half of this dish. Without it, 2 tbsp rice vinegar and a little more soy sauce gets the colour and depth back — the same vinegar is in yuxiang eggplant and dan dan noodles.
• Home-made chilli oil is much better: pour oil at about 160C over fine chilli flakes and let it cool (chilli and heat).
• Dress it at the last moment. There is really only one way to fail at this dish, and that is dressing it early.
• Leftovers are a different food the next day. The crunch is gone but the seasoning has gone all the way in and it eats like a pickle. That is fine — do not throw it out.