1. In an electric griddle or large frying pan over medium high heat, add grapeseed oil. Brush sliced mortadella with jerk paste, add to frying pan in a single layer. Cook for 30 seconds per side. Reserve.
2. Shred the iceberg lettuce finely, add to a big bowl of ice water, allow to sit in the water for 15 mins, then dry in a salad spinner. Repeat the same process for red onions. Reserve.
3. Toss the pineapple cubes, shredded cabbages, carrot & coriander in a large mixing bowl.
4. Whisk together all the ingredients in the vinaigrette. Pour over pineapple cabbage slaw.
5. Build your sandwich by spreading mayonnaise on the bread, then placing the jerk mortadella slices, iceberg, tomato, & onions. Serve the coleslaw on the side or pile it onto your sandwich.