Bake in moderate oven 180degC (350degF)(lower if fan forced) 12 – 15mins or until golden brown.
Allow to cool in tins.
Basic white sauce; melt butter and whisk in flour, cook for 1 minute; add milk slowly, off stove, while whisking; put back on stove and heat to boiling, whisking all the time; add mustard, pepper, salt, paprika, parsley and shallots - and whatever other ingredients you wish.
Spoon prepared filling into cases, place on oven trays.
Bake 180degC (350degF) unless fan forced, 12 mins or until filling is heated through.
Salmon filling; Add salmon, and cheese if you are using, to basic filling.
Asparagus filling; Stir until cheese melts so work quickly before basic sauce gets cool; add to basic sauce.