Now these are not Helford mussels or even Loch Eriboll, but at £3.20 or £6.40 for four people it's a dirt cheap starter.
Moules Marinière.
Diced Onion
Diced Garlic
Butter
Cream
Parsley
White wine
Freshly ground S & P.
It says on the pack cook from frozen but I prefer to defrost..
Sweat onions & garlic off, bung in les moules, S&P, & a slug of wine rattle around with lid on for 2 minutes, chuck in cream....
Sprinkle with 'ripped parsley or anything green....drink more wine...

Nb: For the gourmet chef's amongst us one could then do a quick white wine reduction napping sauce.