Begin by preheating your oven to the maximum temperature.
Next, using a sharp knife, score the skin of the pork belly by making straight, parallel lines with 1 inch of space between each line.
4 ½ lb pork belly
Process fennel seeds and sea salt in a pestle and mortar or coffee grinder, then rub the mixture all over the skin of the pork belly, making sure to get inside the scored lines.
2 tablespoon fennel seeds
In a baking dish, place fennel pieces, thyme, garlic, and cooking fat, seasoning with salt and pepper. Place the pork belly on top of the fennel, skin side up, and bake in the oven for 10 minutes before reducing the temperature to 325°F and roasting for an hour.
4 fennel bulbs, 5 cloves garlic, 3 tablespoon cooking fat, Bunch fresh thyme, Sea salt and freshly ground black pepper
Add 3 cups of water after the hour, then return to the oven for another hour.
Remove the fennel and set it aside, then place the pork belly back in the oven for another hour until the skin is crispy and the flesh is tender.
Serve with the cooking liquid as a gravy and use the reserved fennel tops for garnish.