Pick Roma tomatoes that are small and seedless, suitable for spoon sweets. Blanch them in boiling water (place in boiling water for 1 minute), strain and peel them. 

Spread them on a platter in rows and sprinkle them with plenty of sugar.

Set them aside for 24 hours. Then, collect the juice that the tomatoes have let out and sprinkle the sugar with it. 

Add an additional cup of water and boil for 15 minutes. Press a peeled hazelnut into each Roma tomato and put them into the syrup to boil for 2-3 minutes. 

Remove from heat and let the sweet sit until the next day. Place back over heat, add the lemon juice and boil until the syrup thickens. Add the mastic, let it cool a little and store in jars. 

The sugar that you sprinkle the tomatoes with is not included in the 1300 g of the ingredients, it is extra.