Cut the pineapple top off and slice off the skin. Cut out any remaining spikes. Cut the pineapple in half lengthways and then cut again so that it is quartered. Proceed to cut into small chunks. Line a tray with baking paper or a silicone mat and place the chunks onto the tray ensuring none are overlapping. Place the tray in the freezer and allow chunks to freeze (overnight). Once frozen, place the chunks into a snap lock bag and keep in the freezer for up to 6 months. Use as needed.