Step 1

Pat the pork belly dry to remove any excess moisture. Score the fat side of the belly in a wide cross pattern, cutting into the fat but not as far as the meat. Turn belly so meat side is up. Lay tenderloin on top and trim the end if it hangs over the end - you want it about the same length. You can either tuck the chopped off piece in any thinner bit inside or use for something else. Alternatively you can cut and lay two pieces side by side if it is very long (as I did).

Step 2

Toast the fennel seeds a minute in a dry skillet/frying pan until fragrant. Crush them with a pestle and mortar and add all other ingredients. Start with the garlic, which should be roughly chopped then crushed with the seeds. Only use 1tsp salt at this stage. Alternatively, add all ingredients to a small food processor and pulse. Either way, you want a relatively smooth paste.

Step 3

Spread about 3/4 of the paste over the meat side of the belly and around the tenderloin pieces so they are evenly coated.

Step 4

Tie up the belly by rolling the belly around the tenderloin and tying at one end, then using the long end of the string, move along about 1-2in and loop again by threading through and keep repeating until you reach the other end, then tie off at the other end. Each time you loop/tie, pull the string tight so it's against the meat but not too tight that it squeezes the loin out.

Step 5

Rub the remaining herb paste over the outside of the belly along with the additional 1/2tsp of salt.

Step 6

Refrigerate at least a day uncovered. Dab once or twice to remove any excess moisture.

Step 7

On day of cooking, allow the pork to come to room temperature as you preheat oven to 275F/135C.

Step 8

Roast for approx 2hrs. (Note this is time if both tenderloin and belly are about 2lb each; give a bit less or more if smaller/larger). You're looking to cook until a meat thermometer gives internal temp of 150F/65C.

Step 9

Increase oven temperature to 450F/230C and roast until the skin is brown and crisp but not burnt - keep a close eye on it. This will be around 15-25min.