Start by making a small shallow cross, with a sharp knife, at the pointed end of each Tamarillo. Drop them in a pot of boiling water and turn the heat off. Cover the pot and let them sit in the water for 5 minutes.
Drain the water and refresh them in cold water. You should be able to peel off the skins easily now. Trim the top off each fruit and cut them into small pieces. Put them into a heavy bottom pan.
Dice the pears. Blend them with the orange juice till smooth. Add this to the saucepan and place on the stove top. Add the sugar and stir till the sugar dissolves. Bring to a boil. Then turn down the heat, add the orange zest and let it simmer, stirring occasionally.
Once it thickens to a jam like consistency (this won’t take long), stir in the butter. The butter will give the jam a nice shine and flavour. Let it cool and transfer to a sterile jar.