Set a large pot of water over high heat, add the potatoes, and bring to a boil. Simmer until tender. Drain the pot, then return the potatoes to the pot. Turn the heat to low. Let them steam a couple minutes.
Add the remaining potato ingredients and mash it all well. You want the potatoes to be delicious, and fluffy. Set aside for now.
FILLING
Heat the butter in a large, wide pan over high heat. When it just barely starts to brown, add the venison and brown well; salt it as it cooks. Take your time here, because you want good browning, not just gray meat. Remove and set aside.
Add the onions to the pan and some more butter if you want. Brown the onions well, too, over medium-high heat. Add the carrots, parsnips and garlic and cook another couple minutes.
Set a large Dutch oven or similar pot over medium heat. Preheat the oven to 400°F.
Add the browned meat and onions to the Dutch oven, plus all the remaining ingredients -- except for the last 1/2 cup of shredded cheese. Stir well and bring to a boil. Boil this down, stirring often, until the mixture is wet, but not soupy. This should take 5 to 10 minutes.
Pour the meat mixture into a 9x13 casserole dish or other similar baking dishes. Leave about 1 inch space for the potatoes. cover the casserole with the potatoes and make the surface irregular, which will make nice brown marks. Sprinkle that last 1/2 cup of cheese over the top. Bake until everything is pretty and browned, about 25 minutes.
Notes
Literally any ground or small-diced meat will work here, from beef, mutton and lamb to deer, elk, pronghorn, moose, caribou, wild turkey, etc.
Keys to Success
The alcohol you choose to cook with should be what you drink with your shepherd's pie, so a decent dry red or, ideally, an English ale. Can't use alcohol? Use more stock.
The Maggi really adds something to this dish, but is not 100% required.
If you like this filling, it makes a great filling for venison pasties, too.
Once it goes into the oven, you are really just heating things up and looking for pretty browning on top. Everything is already cooked, so the timing is approximate.
The ramekin idea elevates shepherd's pie to a dinner party or date night dish. Definitely give it a whirl.