Buro is freshwater fish fermented in salt and ba-aw (ba-ao, bahaw, steamed rice). It is the foulest smelling edible thing in all the whole wide world, but ironically, it is eaten as an appetizer.
Buro is actually a means of preserving seasonal freshwater fish from the times when electricity has not been invented. The prized fish dalag (mudfish), which comes out of hibernation during the rainy season, is salted and fermented with salted cooked rice to preserve the surplus. So are the native tilapia - small, thin and black - and the rare gourami, which burrow in mud during the dry spell.
These are still the preferred fish to be fermented in a buro today, still as a means of preserving, but more as a way of keeping on with tradition. Nowadays it has actually attained the status of a native delicacy. The buro'n tilapia and gourami are the more common, with the buro'n dalag - since the fish is more rare, the flesh more tasty - commanding about Php250/kg.
I know buro is eaten in other places in the country, like burong talangka (salted fermented mud crabs) in Bulacan, burong hipon (small shrimps fermented in rice) in Pampanga, burong mustasa (salted mustard leaves in water) in Cavite, plus we also have burong mangga (salted unripe mangoes in water) in Pangasinan.
In Pangasinan, though, when you speak of buro - without any qualifier - you refer to the fish fermented with rice. The tang and fermented taste of buro is much, much more pronounced than any other buro outside the province. It is as sour as any spoiled food if you have ventured to eat some (I haven't, but I eat buro).
It is actually indescribable, and those who did not grow up with buro being served on the table will be really turned off by the smell alone. When I was a kid I could not tolerate it on the table if it were placed in front of me. But you get used to it, and once your tastebuds have desensitized a little, you will find that because you're eating it, it will propel you to eat a lot more than what you usually do.
I find this to be the greatest irony of all.
The process of fermentation is pretty straight forward - de-scale, de-gut and clean the fish, rub with sea salt, then mix with cooled steamed rice also mixed with salt. Store, preferably in a covered banga (clay pot) although nowadays it is kept in a plastic container. In three days the buro has fermented well enough to be eaten.
When in season, unripe, julienned labong is topped on the buro before it is fermented.
To tame the taste a little, fresh buro is sauteed with lots of peeled, thinly sliced ginger root and tomatoes. This somewhat defeats the idea of buro, because the tomatoes will shorten the buro's shelf life. But the sauteeing adds to the appeal of buro, enriching the flavors.
Buro is not eaten as an appetizer per se, but small amounts - pea-sized - is eaten along with every spoonful of the meal. It pairs excellently with any native viand and vegetable dish - usually fried or grilled fish, pakbet and dishes cooked in bagoong.
They say that not everybody can make buro - and I agree. Despite the small number of ingredients and the simplicity of the process, not all buro made come out the same.
I have smelled, and not eaten, the buro made by a grand-aunt, who had been the subject of so many grand green jokes and snickers from many of her housemates because of the smell of her buro. It had been called not just ma-anglit, but also ma-ampap. I am not going to translate what these two words mean for purposes of, uhm, sensitivity? delicacy? (let's just say I don't want to offend anybody's sensibilities). But if you're not from the province go ask your Pangasinense friends. You will get my drift.