Prepare the pork belly:
Preheat oven to 220°C (430°F). Pat the pork belly dry with paper towels. Rub the skin with olive oil, salt, pepper, and fennel seeds (if using).

Roast to crisp up the skin:
Place sliced onion, carrot, and garlic in a roasting tray to form a base. Lay the pork belly on top, skin side up. Roast for 30 minutes to blister and crisp the skin.

Lower heat and braise:
Reduce oven temperature to 160°C (320°F). Pour in chicken stock and vinegar (careful not to wet the skin). Cover tray with foil and roast for another 1½–2 hours, until pork is tender.

Final crisp (optional):
Remove foil, turn oven back up to 220°C for 10–15 minutes to re-crisp the crackling. Watch carefully to avoid burning.

Boil the potatoes:
While the pork rests, boil potatoes in salted water for 15–20 minutes or until fork-tender. Drain well.

Mash and season:
Mash the potatoes with butter and warm milk. Add salt and pepper to taste. For extra creaminess, add a splash of cream or roasted garlic.

Serve:
Slice the pork belly and serve over a generous spoonful of mash. Drizzle with pan juices or a gravy made from the roast tray.

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