This recipe (thanks to Nobu) .. takes a while...
The method is fairly straightforward - each step is fairly easy, but you have a lot of waiting.
Step 1
60 g of granulated sugar
100 ml of water
Dissolve the sugar in the water over a low heat for 10-15 mins - trying not to simmer it. Remove from heat and allow liquid to cool to room temp.
Step 2
Cut a cross just into the skin on the bottom of the tomato. Dip in boiling water for a few seconds.. Then soak ice-cold water. The skin should easily peel off.
Soak the tomatoes in the sugar-water overnight.
Step 3
100 g dark vegan chocolate
100 g white vegan chocolate - if you can find it.
Dab the tomatoes dry...
Put some dark chocolate into a (heat-resistant) small bowl and put the bowl in some boiling water. Allow the chocolate to melt. When it is a liquid, lower the tomato by its stalk into the melted chocolate. Roll it slightly so that the chocolate goes halfway up the side of the tomato.
Allow to cool somewhere cold-ish.. in a fridge or in the snow.
(My white chocolate was not so good at melting.. but I could remove it from the tomato, and there was enough dark chocolate to do both (and a banana too)!!