h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

the secret to a good roux (the butter and flour mixture) is to leave it cook for awhile. this does 2 things. firstly it allows the roux to form a golden colour. secondly it changes the flour taste to something less doughy, which is quite unpleasant. that horrible white sauce you used to get on fish in cafeterias in the bad old days? that's an undercooked roux at work. TV chefs still keep undercooking roux. it is my second most hated TV chef messup. (behind putting garlic in at the same time as onion when it cooks much much faster. the resultant metallic taste is diabolical.) in french cuisine for some dishes the roux is allowed to get very dark, a black roux. apart from the consistency, these are the principle reasons you make a roux rather than just whisking together flour, melted butter and milk.

this is one of the cornerstones of good cooking. from the roux you can make the article-mentioned cheese sauce. it is also the foundation of a good gravy. (just add stock and pan drippings in place of the milk. you can substitute some of the fat from the roast for the butter) with just the roux and milk/cream (and usually nutmeg) it is a bechamel. any number of variations on this theme and every aspiring cook should know how to make a decent roux sauce.

for a cheese sauce i would usually add a measure of mustard and perhaps some parmesan or romano as well as cheddar.

Mmmm, hungry belly: cheese sauce is wonderful, and should be made from a roux, as described. I have two further tips which make for a REALLY good cheese sauce.

Flavouring the milk before making the sauce - heat it with half an onion, a carrot, and a stick of celery (all grated), and a bay leaf (garlic can go in too), for five minutes, then leave to sit for half an hour. Sieve it before making the white sauce with it.

A mix of cheeses is a must - at the very least cheddar and parmesan.
If you are lucky to have the heel of a hard cheese, a little smelly, in your fridge, chop it into large chunks and drop it into the sauce as you cook it. Let it simmer for however long you have patience. Fish out the lumps of cheese-heel. They will have given the sauce a really deep flavour. And that's better than binning them.

Mustard is good. So is nutmeg.

flavouring the milk is a great idea. and i'm glad to see celery get a mention. along with turnip it is one of our most under rated vegetables.

i'm not a great cook, but one thing i think you muct do when making cheese sauce is to warm the milk to at least room temperature before adding to the butter/flour mix. cold milk causes "issues".

only if you add all the milk at once, which one sees tv chefs do too often. (i once saw one tv chef, who shall remain nameless, make little balls of butter/flour mix and add them progressively to a fish soup until it thickened. i can only describe this as a crime against food.) after the flour and butter mix has browned you remove the pan from the heat and add a few tablespoons of milk to create a slurry. most of this milk will instantly turn to steam but enough will remain to incorporate and begin the process. add a few more tablespoons of milk, mix so it is smooth and return to the heat. you can then start adding larger amounts of milk until you have the required consistency.

i only add enough milk at a time to maintain a slow boil. this way by the time you are finished the roux is properly cooked through and will not taste doughey