Step 1Finely grind the mustard, cumin and fennel seeds, the bay leaf, juniper berries, coriander, pimenton, brown sugar, salt and pepper in a spice grinder. Coat the pork with the spice rub. Refrigerate the pork for 1 hour.
Step 2Heat the oven to 325 degrees. Roast the pork until it reaches an internal temperature of 155 degrees, about 1 hour and 15 minutes. Remove from the oven, loosely cover with foil and set aside 10 minutes before slicing.