Proper Bechamel - Broccoli & Cauliflower Cheese A tutorial

2 TBS butter
2 TBS plain flour
285ml of hot milk (1 1/4 cups)
salt
freshly ground black pepper

Melt the butter in a heavy
bottomed saucepan over medium heat.  Whisk in the flour and cook,
whisking constantly until the flour is cooked out and bubbles a bit.  Do
 NOT let it brown.   This will take about 2 minutes.   Whisk in the hot
milk, slowly, whisking constantly until the milk is all whisked in and
the sauce thickens.   Bring to the boil.  Stir in the salt and pepper to
 taste. Lower the heat to very low and continue to cook, whisking, for
an additional 2 to 3 minutes longer.   Remove from the heat.  If you are
 using the sauce later, cover the top with a round of baking parchment
to prevent a skin from forming.  (You can also pour a very thin layer of
 milk over top which works in much the same way.)

Variations:

Thick
 Cream Sauce – Use 3 TBS of flour to 225ml/1 cup of milk.  This is the
consistency needed for souffles and meat, poultry or fish croquettes.

Lemon
 Cream Sauce – Just before serving, beat in 2 large egg yolks, 6 TBS of
butter (1 TBS at a time) and 1 TBS fresh lemon juice

Cheese
 Sauce – Stir in 60g/1/2 cup of grated Cheddar cheese during the last 2
minutes of cooking, along with a pinch of cayenne pepper.

1 1/2 pints milk (3 cups)
1 bay leaf
1 onion, halved
a few whole cloves
freshly grated nutmeg
4 TBS butter
4 TBS flour
salt and freshly ground pepper to taste
1 tsp Dijon  mustard
120g mature farmhouse cheddar, grated (1 cup)

To finish:

First make the bechamel sauce.  Place the onion, stuck with the cloves
and the bay leaf into a saucepan with the milk.  Bring just to the boil,
 then remove from the heat and allow to stand for 30 minutes to allow
the onion and herbs to infuse the milk with their flavour. At the end of
 half an hour, melt the butter in a saucepan.  Whisk in the flour.  Cook
 for one minute, then slowly whisk in the infused milk, discarding the
onion, bayleaf and cloves.  Whisk and cook until thickened.  Turn heat
to very low and allow to cook for 15 to 20 minutes, stirring frequently
as to prevent it from catching.  Remove from the heat and then whisk in
the grated cheddar and Parmesan, along with the mustard.  Flavour with
some grated nutmeg and season to taste with salt and pepper.  Set aside.

Pre-heat the oven to 200*C/400*F/ gas mark 4.

Place in the heated oven and bake until it begins to brown in places and the sauce is bubbling.  (20 to 25 minutes) Serve hot.