As I mentioned on Wednesday, steaming is a very common way of cooking fish in Chinese cuisines — a whole steamed fish can look pretty spectacular as the centrepiece of a banquet. However, the head is not left on simply because it looks good; there's plenty of flesh in there for eating, and in fact the cheeks are considered to be the most delicious part of the entire fish (I have no personal opinion on this, since I still haven't mastered the art of extracting flesh from cheek). Indeed, the restaurant (Golden Day) where I took the photo in this post actually offers steamed fish head (魚頭/yú tóu) as a dish in itself, and fish head dishes are popular in other Asian cuisines too (e.g. fish head curry in Malaysian cuisine).
In Cantonese (Guangdong) cuisine, a steamed fish might be flavoured quite simply and subtly with ginger and spring onions; this is the 清蒸 (qīng zhēng) or "clear steamed" style that Sung quite rightly berated me for not mentioning in my last post. Red Cook has a recipe for clear-steamed seabass (清蒸鱸魚/qīng zhēng lú yú) that exemplifies this technique (see also Ah Leung's comment on eGullet, Steamy Kitchen's Chinese steamed fish recipe, and Helen Yuet Ling Pang's post about her mother's steamed fish recipe).
Other regions have their own preferred styles too. Teochew-style steamed fish might be flavoured with sour plum, mushroom, tomato, and preserved vegetable as well as the usual ginger and spring onion — see Lily's Teochew-style steamed pomfret or Tepee's version on eGullet. I also recently read about a specialty of Yangzhou (a city in Jiangsu province, located on the bank of the Yangtze River) — steamed mandarin fish in vinegar sauce (though sadly I am yet to find a recipe for it).
For this post, though, I'm focusing on Hunan-style steamed fish, which is more likely to come with chopped salted chillies (剁椒/duò jiāo or 剁辣椒/duò là jiāo — 剁 is chopped/minced, 椒 is chilli/pepper, and 辣 is spicy) and perhaps a generous serving of minced garlic too. According to Henry Chung in his Hunan Style Chinese Cookbook, steaming is the second most popular way of cooking Hunan food (regrettably I seem to have failed to note down what he counts as the most popular).
Fuchsia Dunlop's book on Hunan cuisine, Revolutionary Chinese Cookbook, describes 剁辣椒 as a hot, sour, salty preserve which is "brilliantly, beautifully red in colour" and "one of the most distinctive Hunan seasonings". You can buy it ready-made in jars, but it's simple to make — coarsely chop some fresh red chillies (include the seeds too), mix them with salt, pack them into a clean jar, screw the lid on, and let them sit at room temperature for a couple of weeks. Ms Dunlop's suggested proportions are 500g chillies mixed with 60g salt, and another 15g salt sprinkled on top before sealing the jar (see the Tigers And Strawberries post on 剁椒 for volume measurements and additional commentary).
To steam your fish, you'll first need to make sure you have suitable equipment — specifically, something big enough to fit a whole fish in! The usual way to do this is in a wok — put a rack/stand in the bottom, add water, put the fish on a large plate on top of the rack, and put the domed lid of the wok on top of all that. If you don't have all those things, check out Helen Rennie's suggestions for an improvised fish steamer. Helen also gives timings: 8 minutes per inch of thickness for whole fish (measure the thickness at the thickest part).
The Revolutionary Chinese Cookbook mentioned above offers a specific recipe for steamed fish with chopped salted chillies; I won't reproduce it here, but will give the gist. Before placing the fish in the steamer, make several diagonal slashes in the thickest part so the flavours can penetrate, then rub it with 1 Tbsp Shaoxing wine. Now stirfry 1/2 tsp fermented black beans and 1 1/2 tsp finely chopped ginger in 2 Tbsp oil, until fragrant; set aside and clean the wok ready for steaming. Place 20g unpeeled smashed ginger root and 1 smashed spring onion on the steaming plate, then put the fish on top. Cover the fish evenly with 60g chopped salted chillies, then scatter the black bean/ginger mixture on top. Steam until done.
Edit, October 2010: If you want a specific recipe to follow, TravelChinaGuide has one, though note that they don't specify that the chopped red chillies should be salted ones, and they omit the black beans.