Roast Chateaubriand with a Bearnaise sauce

LAST week I completed my discussion about vitamins, this week I want to discuss essential minerals.
Essential minerals can be divided into two categories; macro and micro-minerals. Macro-minerals are defined as minerals that are present in the average human body of five grams or more, they are: Calcium, phosphorus, magnesium, sodium and potassium. Micro-minerals,  (which I will discuss next week) are present in quantities a lot smaller than five grams.
Calcium: The most abundant mineral in the body, calcium is needed for bone and tooth formation and for a healthy nervous system. The average adult has 1kg of calcium in their body. Dairy products are a good source, as are non boned fish such as sardines and whitebait.
Phosphorous:  Is also required for bone and tooth formation and keeping the body’s cell walls intact.  It has the same dietary sources as calcium.
Magnesium: Is required to activate enzyme function and necessary for nerve function and bone formation.  Any green-leaved vegetable is a  good source.
Sodium: This regulates the water content of the body, it is found in all foods and of course, table-salt. Spain (especially all of the areas served by The EWN), is a hot country and salt is lost during perspiration, the resultant deficiency can result in muscle cramps.
Potassium: Necessary for the normal functioning of cells, deficiency is rare because potassium is found in most foods; bananas are a particularly good source.
This week’s recipe: (Chateaubriand: ‘A large steak cut from the thickest part of a fillet of beef.’)
Roast Chateaubriand with a Bearnaise Sauce.
Serves 4
1kg Piece Chateaubriand Steak (Trimmed)
1 tablespoon olive oil
Pour the olive oil into a frying pan on a medium heat.
Sear it on all sides to seal in the juices.
Place in an oven tin and then into an oven pre-heated to 200 Celsius (conventional) or 180 Celsius (fan).
Cook for 25 minutes per pound plus 25 minutes for medium to well done. 20 minutes per pound for rare to medium.
When it is cooked, take it out of the oven, cover and let it rest for 10 minutes.
While it is cooking make the Bearnaise Sauce.
140ml white wine vinegar
2 whole shallots, chopped
1 bunch tarragon, coarsely chopped
Salt and freshly ground black or green pepper, to taste
170g butter
4 egg yolks
Place the wine vinegar, salt, pepper, tarragon into a heat resistant bowl and then place in a pan containing water, heated to boiling.
Boil until the volume has been reduced in volume by half.
Strain and discard onion and tarragon.
Pour back into the bowl and reduce heat to a very gentle simmer.
Add the butter and stir until melted.
Add egg yolks and continually stir, being careful not to coagulate the yolks.
Serve.