Soak the Dried Porcini Mushrooms in 1 cup of warm water for 20–30 minutes, then strain and reserve the soaking liquid, chopping the rehydrated mushrooms coarsely.
Trim and cut the Pork Shoulder and Beef Chuck into 1–1.5 inch cubes; slice the Smoked Kielbasa into rounds, dice the Smoked Bacon, thinly slice the Onions and mince the Garlic; shred or thinly slice the Green Cabbage and give the Sauerkraut a quick rinse if it’s extremely sour.
In a large heavy pot or Dutch oven, heat a couple tablespoons of Lard over medium heat. Add the diced Smoked Bacon and cook until it renders and becomes lightly crisp; remove the bacon with a slotted spoon and set aside, leaving the fat in the pot.
Increase heat to medium-high and brown the pork and beef in batches in the bacon fat, searing on all sides to build flavor; transfer the browned meat to a plate as each batch finishes.
Reduce heat to medium and add the sliced Onions to the pot; cook until softened and beginning to color, then stir in the minced Garlic for about 30 seconds.
Mix in the Tomato Paste and cook briefly to remove its raw edge, scraping up any browned bits from the bottom of the pot.
Add the Sauerkraut and shredded Green Cabbage to the pot, then fold in the chopped rehydrated porcini and the Prunes. Pour in the reserved mushroom soaking liquid (strained) to capture that deep umami.
Return the browned pork and beef and the reserved bacon to the pot. Deglaze with the Dry Red Wine, scraping up any fond, then add enough Beef Stock to just cover the ingredients.
Tie the Bay Leaves, a few crushed Allspice Berries and Juniper Berries in cheesecloth (or add loosely and fish out later) and add them to the pot along with the Caraway Seeds, a pinch of Dried Marjoram, a teaspoon or two of whole Black Peppercorns and salt (Salt) to taste.
Bring to a gentle simmer, cover partially, and cook over low heat for 1½–2 hours, until the meats are tender and flavors have melded. About 20–30 minutes before the end of cooking, stir in the sliced Smoked Kielbasa so it warms through and releases its smoky flavor without falling apart.
Taste and adjust seasoning, removing the bay leaves and any whole spice bundles. If the stew is too thin, cook uncovered a bit longer to reduce; if it’s too sharp, a small knob of butter or a teaspoon of sugar can help balance the acidity.
For best flavor, cool and refrigerate overnight and gently reheat the next day — bigos improves with time. Serve hot with rye bread, boiled potatoes, or a dollop of sour cream if you like.
