This dish is in honour of St. David, the Welsh patron saint, whose life is celebrated on March 1. Welsh Caerphilly cheese is slightly salty, with a hard centre, and soft around the edges. Welsh miners would take it underground because the saltiness helped them retain water in the heat, and the hard rind was easy to hold and discard with dirty hands. Originally made with vegetarian rennet, much is now made with animal rennet, so check with your supplier. Good English cheddar is a great alternative. This sensational dish makes a robust first course or a side dish.