Razor clams are becoming available in some of the fishmongers in my area. I first ate these with my wife when on holiday in Majorca and really enjoyed them, but we didn't find out how they were cooked. They were served hot, on the shell, with a bit of buttery, garlicky sauce.
I've recently tried cooking them at home twice and both times they were tough. The first time I took the white fleshy parts out of the shells (discarded all the yucky looking bits) and pan fried them very briefly in butter, in a similar way to scallops (which I cook often and very successfully). They tasted good but were very, very chewy. I didn't know if this was because I'd over- or under-cooked them, but generally with shellfish less cooking time is better, so I only gave them a couple of minutes over a fairly gentle heat, with the butter bubbling but not sizzling fiercely.
The second time I left them on the half-shell, dotted them with bits of garlic butter and popped them under a hot grill for a couple of minutes. They were even more chewy than the pan-fried clams!
Both times the clams were definitely cooked through.
So, any bright ideas? Are they just tough anyway? (though I don't remember the ones we had in Majorca being tough). Anyone got any experience of cooking these shellfish?