To be honest, I am not fully certain what halabos is as a cooking technique. But what I've been taught by our kusinera (home cook) a good 25 to 30 years ago is that it is a "cross" between steaming and boiling. How is this so? Well, a very small amount of water or stock is used to cook the dish (usually seafood, especially shrimps). The dish would be cooked largely by the steam generated by the water or stock. (I hope that made sense because I don't really know how to explain it...)
But to demonstrate it, here is halabos na tahong (mussels).
The recipe -
1 kilo tahong (mussels)
4 to 5 thin slices of ginger
4 cloves of garlic, smashed
1 small onion, sliced
1 medium tomato, sliced thinly
1 to 2 cups water
salt to taste
1 to 2 pieces finger chili
handful of dahon ng sili (pepper leaves)
Wash the tahong well and remove any dirt and "hair". Drain.
the ginger, garlic and onions. Add the tomatoes. Stir fry a couple of
minutes then add in the mussels. Pour in the water and cover the pan.
When the water starts to boil, throw in the finger chili and sili
leaves. Season with salt, to taste. Stir occasionally. When the
mussels open, turn off the flame. Do not over-cook. If the water fully evaporates, add hot water in half cup increments.
broth (what little of it is left, that is) is very tasty and I always exercise (what I call) cook's
privilege which means no one else gets the broth but me! (hwa-hwa-hwa.)
*I like using a wok for this dish. I find it easier to stir the mussels around so that they cook evenly.