Remove the rind from the bacon if necessary and discard. Chop the bacon and place in a frying pan over a medium heat. Cook and stir for a few minutes then add the onion and continue to cook until soft. Remove from the heat.
Place the callaloo greens in a large saucepan over a medium high heat. Pour in the stock then add the onion, bacon and bacon fat; stir then lower the heat and allow to cook for a few minutes. Add remaining ingredients and stir until well blended and thoroughly mixed, about 10 minutes. Serve hot!
Try searching for the callaloo online or in specialty shops, in a pinch substitute with 2 bunches of fresh Swiss chard or kale, with the tough stems removed and leaves chopped.