The empire of raw fish eating encompasses many realms but the basic idea is very clear. The freshness of the fish is paramount.
Even in older times, people were intuitively aware of the need to "sterilize" the surface of the flesh. They may not have not known about bacteria and clean workspaces but they had empirically figured out that the surfaces of the fish get contaminated quickly in a hot climate.
The solution was a quick bath of the fish in an acidic medium — lime, lemon or calamansi juice, various vinegars, etc.
Different cultures produced variants that lie along a spectrum — sashimi and sushi (Japanese), kinilaw (Filipino) and ceviche (South America and then transmitted further via the Spanish Empire.)
They range between raw and "cooked" via acid. There's also some form in pickling in the mix.
Sashimi for all its vaunted "heritage" is only possible thanks to modern-day fish processing. It's only modern freezers that allow fish to be consumed safely.
Sushi is an older idea where fish were placed with vinegared rice and allowed to partially ferment to develop intense umami flavors. This older style of sushi is seldom found any more. In fact, even slightly recent forms of sushi (Edo-sushi) are rarely found today. The modern-style involves raw fish placed over mildly vinegared rice. (A full treatment of all the sushi styles would take up a book not a blog post!)
Ceviche is widely known these days. Raw fish is mixed with lime juice, spices, peppers, cilantro and sometimes all kinds of incongruous ingredients (avocado?) — this idea from South America spread across the globe with the Spanish Empire. The idea is that the intense acid "cooks" the muscles of the fish. It's easy to prepare to keeps easy with modern refrigeration. No wonder it's a hit at restaurants since it can be made ahead of time.
Kinilaw (or kilawin sometimes) is an ancient style of Filipino cooking. Even though it's tempting to assume that the idea came with the Spanish Empire, the evidence overwhelmingly suggests it was an original ancient indigenous idea that the Spaniards encountered and recognized as being analogous to something they already knew.
In fact, for an ancient idea, kinilaw comes closest to the modern-day ideal of sashimi. The fish are bathed in an intensely acidic broth but they are consumed right away within seconds. Kinilaw connoisseurs can feel the toughening of the fish fibers as the minutes tick away.
It's served with rice. Rice is everywhere in the Philippines even for breakfast! The CC's passion for food has limits. More rice? Again?!? SIGH.
There are also added vegetables — radishes are classic but the CC bets that halved summer cherry tomatoes would be killer too from the umami. There is also lato but you can't find that outside the Philippines. SIGH.
As would the dried anchovies known as dilis in the Philippines although the idea of pairing dried and fresh fish would be looked upon as total heresy. The same idea with dried fish is a "separate" dish. SIGH.
A word about calamansi — these intensely flavored citrus limes the size of a small marble are unique. If you can't find them, the next best bet are the yuzu you find in the Japanese markets. If you can't find those, use a mixture of orange and lime juice but you will not reproduce the intensity and uniqueness of calamansi.
Kilawin is also made with cooked pork and goat. It's a pretty general idea and the general etymological difference between kilawin and kinilaw seems to be whether it's cooked meat or fresh fish. (This is a bit unresearched and sorta folksy, and the CC might be wrong.)
Given the sashimi nature of the dish, if you want great kinilaw, you must make it yourself. There is no other choice. At the CC's farmers' market, there is a local fisherman supplying two kinds of sashimi-grade seafood — tuna and scallops. Hence, the CC makes tuna and scallop kinilaw since that is what is possible outside of the absurdly magnificent "wet markets" of the Philippines.
1 shallot (diced fine)
1" ginger (cut into fine slivers)
2 garlic cloves (diced fine)
2 Thai bird-eye chillies (diced into very thin rounds — add more for spice)
1/2 cup coconut vinegar
6-8 calamansi (squeezed fresh)
salt (read below)
fresh black pepper
2 red radishes (cut into thin half-moons)
1/2 lb sashimi-grade tuna (diced)
6 scallops (cut into 4 half-moons each)
Mix all the ingredients except the fish together. Taste. It should have an intensely sour taste but it should also be "rounded". This is hard to explain but easy to taste. You typically won't need salt but you might need a pinch. It should sit together for at least 30 minutes for the flavors to "blend".
Store the mixture and the diced fish in the fridge separately. Mix right before serving.
Tick tock, tick tock, tick tock. The clock is ticking. Eat right away if you want magic.