Preheat the oven to 170°C.
Crush the salt, peppercorn, fennel seeds, garlic and rosemary using a pestle and mortar. Add the mustard and the oil.
Rub the rack with this mixture then put it in a baking tray. Cover the tin with foil then put it in the oven for an hour and a half.
Meanwhile put the glaze ingredients into a small saucepan and bring to the boil. Reduce it to half to a thick syrup. Let it cool.
When the ribs are cooked, brush the glaze all over the ribs and put it back into the oven. Turn the heat up to 200C and bake for about 10-15 minutes (uncovered), until the skin is dark and sticky.
Wrap the ribs in the foil and rest for 10 minutes before cutting them up along the bones.