Make the crust by using a food processor to finely blend the walnuts and raisins or dates to create a dough-like mix. If it isn't coming together so well, add a tablespoon of water to get the mixture started.
Take your tart shells and line them with saran wrap and the press the dough into the shells.
Use the food processor again to blend the avocados, lime juice, lime zest and honey into a very smooth pudding-like mix. Make sure you taste this, you may need to add more lime or honey depending on your taste preferences.
Pour the lime mixture into the tart shells and add kiwis for decoration.
Put in the freezer for about 30-60 mins, or until the lime mixture has the consistency of mousse.
Take out and lift the saran from the mold and serve immediately. Enjoy!