Like many long-cooked meat dishes, this one improves if made a day ahead of time and refrigerated overnight.
2 lbs. fresh beef brisket
Maldon or other sea salt and freshly ground black pepper
3 tbsp. lard
8 small yellow onions, peeled and quartered
1 medium leek, trimmed and thickly sliced on the diagonal
3 stalks celery, peeled and thickly sliced
4 small turnips, trimmed, peeled, and quartered
1 tbsp. mushroom ketchup or Lea & Perrins Worcestershire sauce
1 tbsp. anchovy paste
6 pickled walnuts, quartered lengthwise
3 tbsp. pickled-walnut liquor
2 bay leaves
4 cups beef stock
1. Preheat oven to 325°. Generously season beef with salt and pepper, then dredge in flour. Melt lard in a medium deep cast-iron pot over medium-high heat. Add beef to pot and cook until well browned on both sides, about 10 minutes. Transfer beef to a plate and set aside.
2. Reduce heat to medium. Add onions, leeks, celery, and turnips and cook, stirring often, until lightly browned, about 10 minutes. Add mushroom ketchup, anchovy paste, pickled walnuts, walnut liquor, bay leaves, and stock. Return beef and any accumulated juices to pot.
3. Bring liquid to a gentle simmer, skimming off any froth that surfaces, and simmer for 10 minutes. Cover pot and put in oven. Cook until beef is very tender when poked with a skewer, 3 hours, removing cover for final half hour. Remove bay leaves. Use two forks to separate beef into 4 pieces. Transfer to a platter and ladle vegetables and broth over meat. Serve with puréed potatoes, if you like.