Poaching food is a delicate style of cooking, usually for delicate food such as fish, eggs and fruit. Poached pears (left) are one of my favourites.
It’s more a style of cooking than a prescriptive method because it’s hard to gauge the temperature without the use of a thermometer. There’s a bit of guessing and testing involved until you get a feel for it.
There is one thing to remember, and that’s to keep the poaching liquid (water, stock and the like) below simmering point - some chefs refer to shimmering water, just before bubbles break the surface.
Poached chicken is often called for in recipes. It’s one of the hardest to master because on the one hand the chicken needs to cooked through, but on the other, if poached at too high a temperature, it will be tough. Done properly, it will melt in your mouth.
Kylie Kwong in her book Recipes and Stories has a recipe for white-cooked chicken: a whole chicken is poached in simmering stock, that barely has a bubble, for exactly 14 minutes. It is then left to cool in the stock for some hours, after which it will be ready.
I have tried this method with chicken breasts, poaching them very gently for about 10 minutes, and then letting them cool in the stock to finish cooking. The chicken comes out bautifully - soft and moist to touch and taste.