Preheat oven to 400˚F.
Grease your tart tin. I like to use a rectangular scalloped edge tin, but a 9-inch round tin would work as well.
Sprinkle the sugar and cayenne all over the base of the tart tin. Separate the thyme leaves and sprinkle on the base as well.
I like to use a selection of cherry and medium sized tomatoes of different color. Leave the cherry tomatoes whole. Slice the medium sized tomatoes in half crosswise. Scatter the tomatoes into the tin, placing the cut side of the tomatoes up. You want the tomatoes to fit tightly together so continue adding tomatoes until you have achieved this.
On a floured surface, roll out the puff pastry so that it fits your tart tin. Lay the pastry over the tomatoes and tuck the edges of pastry into the tin. Bake in the oven for 25-30 minutes.
Allow the cooked tart to cool for a few minutes and then invert onto your chosen serving dish. I like to sprinkle some more fresh thyme over top before serving. I think this tart is best served warm or at room temperature.