Add all marinade ingredients into a food processor or blender, blending until smooth.
Clean portobello mushrooms well, then pat dry with a kitchen towel, transfer to an oven dish. Pour the jerk marinade over the mushrooms and coat well with your hands, leaving to absorb the flavours for 2-3 hours (minimum) before cooking.
Heat the oven to 200 degrees celsius, adding in the marinated mushrooms and roasting for 10-15 minutes per side.
Once browned and hot, serve alongside your Caribbean favourites!