Preheat the oven to 365°F / 185°C.
Heat the olive oil in a large, deep oven-safe pan over medium heat. Add the leek and sauté until it begins to soften.
Add the garlic, allspice, cumin and optional coriander seed. Stir briefly until fragrant.
Add the shredded carrot and continue cooking until the vegetables begin to soften.
Push the vegetables to one side of the pan. Add the ground beef to the cleared side and cook until browned and completely cooked through, breaking it apart as it cooks.
Stir in the diced ham.
Add about half of the cabbage and cook for 5 minutes, stirring occasionally, until it begins to wilt and lose volume.
Add the remaining cabbage and toss everything together.
Stir in the tomato paste, beef broth, apple cider vinegar and brown monk fruit sweetener.
Taste the cooking liquid before adding salt. Ham and broth can both be salty, so add salt only if needed. Add cracked black pepper to taste.
Cover the pan tightly with its oven-safe lid or foil and bake for 30 minutes.
Remove the lid and bake uncovered for another 30 minutes, until the cabbage is tender and the top has darker caramelized edges.
Let the casserole settle briefly before serving. Garnish with fresh cilantro if desired.