The flavour of the sauce should be of brandy, mustard and spring onion and remember that if you like the taste of the crushed lobster coral you can add this to the Thermidor sauce as well.
Soften some chopped spring onions in an ounce of butter.
Add 1 tbs of flour – mix to a ‘roux’ adding about 2 tsp of mustard powder.
Add half a pint of milk or a mix of milk and cream, and a dash of brandy (to taste).
Heat through until slightly thickened – add cream if too thick.
Chop the cooked lobster meats and add into the sauce heating gently.
Now place the sauce & meat back into the shells and coat with a layer of grated cheese and breadcrumbs.
Put under a hot grill until browned and bubbling.