I've posted a variation of this before elsewhere, but I like the cold-poaching technique, so I thought I'd repost here.
Cold-poaching involves pouring boiling (or nearly boiling) liquid over fish and letting it cool to room temperature. It works best with lean, white, flaky fish. I used Flathead, which worked quite nicely. For liquid, fish stock is recommended, but I used a quick home-made broth of green tea, fennel and chili. I served this with home-made tartar sauce and fennel-mashed-potatoes.
- Place fish fillets in a ceramic or porcelain dish. Remove stalks, dill twigs from one large bulb of fennel. Set aside twigs and bulb. Bring one cup of water to boil per fish fillet. Add fennel stalks, a few dashes of chili flakes, herb to taste (thyme, mint, rosemary), some lemon zest. Add a bag of green tea for 2-3 minutes but remove. Strain liquid and pour over fish, cover and let stand until at room temperature.
- Chop rest of fennel, coat well in olive oil, place in oven dish, sprinkle with a few pinches of rock salt, cover and bake at 180C for about 45 minutes. Remove cover for about 10 minutes or until crisp and caramelized.
- Boil a handful of quartered potatoes for the mash. When soft, drain water, mix in a spoonful of butter, a half cup of milk, one extremely finely-chopped small onion, a clove of minced garlic, rosemary and thyme. Mix in the roasted fennel and stirr to desired consistency. (Hint: Leaving the peel on adds texture to mashed potatoes, but not everyone likes this.)
- For the tartar sauce, mince one clove of garlic, finely chop one small onion, cut 2-3 inches of zest from a fresh and clean lemon, finely chop the twigs from the bulb of fennel. Mix all together, season, and stir into 4-5 tablespoons of mayonaise.
- Serve everything once fish has reached room temperature.
Fish prepared in this fashion has an extremely soft and slightly flaky texture. The lower cooking temperature also brings out very different flavours than that found in fish served hot. You do not need to smother it in tartar sauce, but the lemon and dill made for nice addition to the flavours developped in cold poaching. Broth can be kept frozen and used in cooking later on.
