Continuing in a tradition of dealing with grief through cooking, I've got a batch of the filling for this simmering on the stove, and I figured I'd pass along my recipe. Some parts of this are pretty traditional, and parts are my own addition (and might make a traditional welsh housewife blanche, but oh well).
For the meat, I like to use about three quarters pounds skirt steak or other lower-grade cuts of beef, a quarter pound of heart, and a quarter pound of kidney; however, since most US grocery butchers don't even stock organ meats anymore, if I don't have time to go out of my way to visit to my local butcher (Golden Steer, who truly are fantastic), I'll stick with just the steak. Chop the steak and heart into managable pieces (in the case of pre-chopped grocery store "beef for stew," cut each piece in half), and layer the two in the bottom of a casserole (I usually just use my pie pan for this; this forces me to clean as I go and thus means one less dish at the end). Pour in a tablespoon or two of soy sauce -- this is my secret trick in any gravy or stewed beef dish, espescially when using lower-grade beef; the added umami really brings out the meatiness (I was gratified to see
the pros back me up, too). Let that marinate for a bit, then drain and pat dry with paper towels. Cut up the kidney, patting it dry as well, and dredge the meat in a mixture of flour and black pepper. Heat up about a tablespoon of bacon fat or lard in a heavy skillet, and brown the beef over medium-high heat. Once evenly browned, add a 12-oz bottle of beer of your choice (red wine works too, if that's how you roll), reserving two decent pulls for the chef, and turn the heat to low. Scrape the bottom of the pan well to mix in the pan drippings. Add one medium-large turnip, chopped in a quarter-inch dice, and a handful of frozen peas, along with your choice of herbs and spices (I'm big on oregano in stewed beef dishes). Cover the pan. While that simmers, trim 6-8 medium brussels sprouts, and chop into quarters or eighths, depending on size. Place in the bottom of a heat-safe bowl. Once the turnips are just starting to soften up (remembering that this will have some more time to cook in the pie), pour the hot gravy over the sprouts and mix well (the heat of the gravy and baking the pie will cook the sprouts plenty). This mixture is best refrigerated overnight before adding to the pie, though it can be added right away; it still helps to let it cool a little before baking. Prepare your savory pastry by your preferred method -- people are picky about their pie crust, so I'll leave this part to you. Some of my personal hints, to do with as you'd please: Replace as much of the shortening as you're comfortable to with butter and bacon grease -- I'll generally substitute at least a tablespoon of each. Replace some of the water with brandy; alcohol moistens flour but does not activate gluten, so by using it in place of some of the water greatly decreases toughness; plus, the brandy adds a hint of extra flavor to the crust (thanks to Alton Brown for introducing this technique to my repitoire). Pour about two thirds the filling into the bottom pie shell, then a layer of sliced cheese -- I like a mild but earthy cheese here; I've had good results with gruyere and port salut, but the real fun is looking at what's fresh and cheap at the cheese counter and think "Hmm, wonder how that'd be?" Add the rest of the filling on top, and affix your top shell. Bake till golden brown, adding an egg wash if desired. Allow to cool about fifteen minutes before cutting and serving.