Easy peasy. Single infusion mash way at the top of the spectrum (158 F or so) for a big body and a full, round malt character. You'll notice this finishes a bit high and that's good. A higher FG means more body and flavor at the expense of ending up with a little less alcohol.
I pitched this with a half-gallon starter. You could get away with just a smactivator pack, I suppose, but why risk it? The cask ale yeast is seasonal, I think. If you can't get it, sub in your favorite British strain.
The great thing about the cask ale yeast, though, is it drops out of suspension really nicely without leaving behind any diacetyl. It's very clean at low temps, practically to a level you'd expect from an American yeast. I did a week primary and week secondary. You could easily skip secondary and just bottle after 10 days and still get very bright beer.
If you want to talk changes, I would consider substituting EKG or other good English variety. My US goldings (whole flowers) worked but they really aren't as vibrant as I'd like. Also, this is very malty, if you like things a bit more subtle reduce the aromatic and biscuit malt and mash lower. I like it how it is.
