Duck with Sour or Sweet Cabbage

Pat the duck dry with paper towels and cut into serving pieces (breast, legs, thighs, and wings), removing excess skin if desired.

Heat the lard in a large, heavy-bottomed pot or Dutch oven over medium-high heat until shimmering.

Brown the duck pieces in batches, skin-side down first, until golden on all sides, about 8–10 minutes total per batch; transfer to a plate.

Add the sauerkraut (with its liquid) to the pot and stir, scraping up any browned bits from the bottom; cook for 2 minutes.

Return the duck pieces to the pot and nestle them into the sauerkraut; add the tomato sauce, paprika, peppercorns, and salt.

Pour in just enough water or broth to partially cover the duck; if using borş for a sour finish, add half the amount now; if using unripe tomatoes for a sweet finish, add them now.

Bring to a simmer over medium heat, then reduce heat to low, cover, and simmer gently for 60–75 minutes, until the duck is very tender and meat pulls away from the bone easily.

Taste and adjust seasoning with salt, paprika, or remaining borş (if using) to balance flavors; simmer uncovered for the final 5 minutes if the sauce needs to reduce and concentrate.

Transfer the duck and sauerkraut to a serving platter or individual bowls, ladle the cooking liquid and sauce over the top, and serve hot.