I duly scanned the interweb and came across this interesting blog, which I reproduce here for my benefit, at the risk of boring you, dear reader:
p.s. I used whatever hard cheese I had in my cheese box, and as I had no stout I just used milk. I also added some finely chopped shallot, and some chopped flat leafed parsley, and used french mustard, so it wasnt really much like this recipe, but it was still very good, and definitely worth repeating.
How to cook perfect welsh rarebit
Felicity's perfect welsh rarebit. Photograph: Felicity Cloake
Now, let's get the name thing out of the way at the start. Some suggest that the dish earned its rather peculiar title (and, once and for all, rabbit is the correct form regardless of what this newspaper's style guide says. Rarebit doesn't pop up until some 60 years after the recipe itself first surfaces, although given both have been in use for over two centuries, I think you're entitled to go with either. I prefer rabbit, but to fall in line with the official guidance will suffer rarebit here) from the poverty of that nation. The point was that a Welshman couldn't afford even that cheapest of meats. Whatever the truth of it, I think this does the heavenly combination of crisp toast and molten cheese a disservice; done right, it's certainly no poor relation.
Indeed, according to a 16th-century joke, the Welsh were famous for their love of toasted cheese – St Peter was said to have got rid of a troublesome "company of Welchman" who were troubling the peace of heaven by going outside and shouting caws pobi – "that is as moche as to say 'Rosty'd ches!' Which thynge the Welchman herying ran out of heven a grete pace". And who wouldn't be tempted from eternal bliss by such a prospect? In fact, according to Jane Grigson, rarebits were once common throughout southern and western England, but, with the only Welsh sort still on the menu, it seems they really do know how to do it best north of the Bristol Channel.
The cheese
Delia recipe welsh rarebit. Photograph: Felicity Cloake
Almost all recipes call for cheddar, but I suspect that's simply
because it's what most of us keep in the house – and rarebit is a very
Sunday-evening, empty fridge type of dish. There are other options: Jane
Grigson suggests Lancashire in English Food, as do Simon Hopkinson and
Lindsay Bareham in The Prawn Cocktail Years, where they explain that,
traditionally, a rarebit would have been made from "hard English cheeses
– cheddar, double gloucester, cheshire and lancashire". Mark Hix,
perhaps anticipating a Welsh backlash, goes for caerphilly in his book
British Regional Food, while Delia consigns any such concerns to the
bottom of Lyn Tegid, and plumps for an equal mix of cheddar and parmesan
for the Welsh Rarebit Soufflé in her Complete Cookery Course. 
Nigel Slater recipe welsh rarebit. Photograph: Felicity Cloake
Nigel Slater reckons that caerphilly doesn't have enough of a "tang
to be interesting", and I'm inclined to agree with him – the mild
flavour is lost among the Worcestershire sauce, mustard and stout in Hix's recipe.
However, at the risk of exposing myself as a cheese wimp, I find mature
cheddar too aggressively flavoured – after half a slice, I start to
feel a cheese overdose coming on (and this from someone weaned on
Roquefort). Delia's parmesan obviously just makes the situation worse,
but I'm on to something with lancashire; it has just enough bite to
dominate the dish, without smothering every other ingredient in the
process. The toast
Although I like my rarebit made with seedy wholemeal toast, which I think gives a more interesting texture and a pleasantly malty flavour, I respect your right to use any sort of bread you like (although no one will persuade me of the merits of the Welsh rarebit foccacia, seen on the menu at a pub I recently didn't eat at). That said, it must be robust enough to take the weight of the cheese; anything too pappy will just become soggy. You can help it along by toasting both sides of the bread before adding the topping, as Mark Hix suggests, rather than just one, as in the Prawn Cocktail Years recipe: the outer edges might char slightly on their second grilling, but, as they'll be covered in cheese, you're unlikely to regret this.The liquid
Mrs Beeton recipe welsh rarebit. Photograph: Felicity Cloake
Most rarebit recipes, with the exception of Nigel Slater's quick version,
loosen the cheese with a liquid: milk or ale, in Jane Grigson's
version; cider for Cheese Society; port for Mrs Beeton; or stout, which
comes with the weighty recommendations of both Mark Hix and the Bareham /
Hopkinson team. The cider is too acidic for my taste, and the port, while surprisingly delicious, gives the dish a vinous tang that reminds me more of a Swiss fondue than something from the Black Mountains. (It also turns the cheese a rather scary colour.) The ale isn't bad – it adds a subtle nutty flavour – but once I try a rarebit made with stout, I'm sold.
Simon Hopkinson recipe welsh rarebit. Photograph: Felicity Cloake
It gives the dish a rich malty savouriness which works brilliantly
with the salty tang of the cheese – and there are a number of great
Welsh stouts available too, just to soften the blow of that English
cheese. Nigel, meanwhile, mixes his cheese with solid butter, which
gives a denser, more intensely cheddary topping which I'd hesitate to
describe as anything grander than a simple cheese on toast.The rich bit
Jane Grigson recipe welsh rarebit. Photograph: Felicity Cloake
Such fat, however, is an important distinguishing feature in a proper
rarebit. It could be melted butter, as in Jane Grigson's recipe, double
cream, as in Mark Hix's, or egg yolks, as used in the Prawn Cocktail
Years, but without it, as Mrs Beeton's recipe proves, the cheese quickly
reverts to a rubbery mess (which is no doubt why she advises keeping it
bubbling over a rather nifty-looking "cheese toaster" filled with hot
water, for people to spread on to toast at table). I think the butter makes things rather too liquid and greasy, and by the time I've reduced the double cream with the stout, I'm not sure I can taste it anyway. Egg yolks, however, work brilliantly to soften the cheese to a spreadable consistency, although I wouldn't wait until it's completely cool to stir them in, as Simon and Lindsay suggest, because by this point it has solidified to such an extent that it's difficult to beat back into smooth submission.
Wildcards
The Cheese Society's recipe welsh rarebit. Photograph: Felicity Cloake
Delia uses eggs yolks too, added to a white sauce, and then mixed
with cheese and folded into some whipped up egg whites to make what is,
essentially, a soufflé base, which is then piled on to toasts and
grilled. The airy texture does nothing for me though – gooey should be
the watchword with rarebit.The Cheese Society also has an unusual take on this classic dish. I start by whisking flour into milk, and heating until slightly thickened, then stirring in cheese, breadcrumbs and cider and continuing to cook until the mixture comes away from the side of the pan. The mixture is then whizzed in a food processor, along with an egg and an egg yolk, before it's ready to be spooned on to toast, and grilled.
Seasonings
I like English mustard in my rarebits, just to add a bit of a kick – wholegrain and Dijon are both too sharp here for my taste. Worcestershire sauce is a must, but I can do without Tabasco and cayenne pepper: the mustard adds all the subtle heat the dish needs.Perfect welsh rarebit
Felicity's perfect welsh rarebit. Photograph: Felicity Cloake
Welsh rarebit may be a simple dish, but if even Nigel Slater admits
to a few failures, then it's certainly worth getting the basics right.
This is my perfect version, but, using the same formula, play around
with different kinds of cheeses and beers until you find one that would
tempt you out of paradise. Because if heaven isn't toasted cheese, then I
don't know what is.Serves 2
1 tsp English mustard powder
3 tbsp stout
30g butter
Worcestershire sauce, to taste
175g lancashire cheese, grated
2 egg yolks
2 slices bread
1. Mix the mustard powder with a little stout in the bottom of a small pan to make a paste, then stir in the rest of the stout and add the butter and about 1 tsp Worcestershire sauce – you can always add more later if you like. Heat gently until the butter has melted.
2. Tip in the cheese and stir to melt, but do not let the mixture boil. Once smooth, taste for seasoning, then take off the heat and allow to cool until just slightly warm, being careful it doesn't solidify.
3. Pre-heat the grill to medium-high, and toast the bread on both sides. Beat the yolks into the warm cheese until smooth, and then spoon on to the toast and cook until bubbling and golden. Serve immediately.
