Trim any unwanted fat from the rashers and remove the outer skin if it is still on. (It’s a very good idea to ask your butcher to do this.)
Saute the onion in the olive oil until soft and add the remaining ingredients.
Simmer the sauce for 5 minutes and puree in a blender until smooth. Add water if the sauce is too thick. Heat sauce and simmer pork rashers over low heat fo 10 – 15 minutes in the sauce. Remove rashers and pat dry.
Grill the rashers under a hot oven grill or over hot coals and turn at regular intervals to get an even golden brown colour on both sides. Use tongs to turn the rashers over, not a fork. Baste with the sauce while grilling.
Season with salt and pepper just before removing them from the heat.
Serve with stywe pap (polenta) or mash potatoes and bean or other green salad.
Variation: Add the juice of one lemon and two tablespoons of olive oil to the marinade and leave the Worcestershire sauce out.