1. Make the potato dough: Peel potatoes and cut into 2-inch piece. Add to stock pot, cover with water by at least 2 inches. Cover the pot and bring to a boil, then drop the heat, remove the lid, and simmer until potatoes are fork-tender (about 15 minutes after removing lid).
2. Drain potatoes and let cool enough to touch. Pass potatoes through ricer or mash quickly with fork/masher. Let the riced/mashed potato cool to room temperature before proceeding.
3. Rub butter between fingers into small clumps and drop them into the same bowl as the cooled, mashed potato. Quickly toss potato and butter together.
4. Add flour, baking powder, salt, and pepper to the potato mixture and knead just until the dough is smooth and comes together. If dough won’t come together, add cold water by the tablespoon until it gathers into a ball. Flatten into disk, wrap in plastic, and refrigerate for at least 30 minutes before rolling.
5. Make the beef stew: Heat oven to 325˚.
6. Mix flour with salt and pepper in medium bowl, then toss beef cubes in same bowl until coated.
7. Heat 11-inch cast iron pan until hot on stovetop, then add bacon fat and let it melt. When it’s shimmering, add beef cubes in batches to brown. Do not overcrowd the pan. When beef cubes are browned, remove from pan and set aside
8. Add bacon to pan and render until crisp over medium-high heat, about 5 minutes.
9. Leave bacon in pan and add sliced onions. Stir to coat the onions in fat, then season with salt. Cook until tender and beginning to go translucent, stirring to avoid burning (about 7 minutes).
10. Add garlic, stir and cook another 2-3 minutes.
11. Add tomato paste, stir to combine and cook for 2 minutes
12. Add carrots and parsnips, stir to combine, sauté for about 5 minutes to get some color on the root vegetables.
13. Add parsley and thyme, stir to combine.Add whiskey, stir.
14. Add coffee and stock, stir.
15. Add browned beef and any accumulated juices, stir to combine.
16. Sprinkle over any remaining flour (from tossing the beef) and stir.
17. Bring to a bare boil, then put skillet in the oven and braise for 60-90 minutes, until beef is fork tender. Add a sheet tray on the rack underneath the skillet to catch any spills.
18. While beef is cooking, roll out the potato dough onto a floured surface. Roll dough until it’s about ¼-⅓ inch thick.
19. Dust rolled-out dough with more flour, then roll dough onto rolling pin in order to transfer it to the skillet.
20. Remove skillet from oven when beef is tender. Increase heat to 400˚.
21. Roll dough over skillet carefully, remembering that the skillet is hot.
22. Press dough onto skillet edge, pulling off any overhanging extra dough. Reserve extra dough.
23. Re-roll excess dough into a log or braid, add around the top of the skillet. Crimp edges with fork or fingers.
24. Brush egg wash over crust, cut vents through top.
25. Put skillet back in oven, bake until crust is golden brown, 20-30 minutes.
26. Remove skillet from oven, scoop and serve.