In a large bowl, mix the chopped basil with 1.5 tablespoons of the olive oil and set aside for 5-10 minutes. Stir in the tomato puree.⏱ 10 min
Roll out the puff pastry very thinly (it's probably easiest to do this in 2 halves) and cut out 6 circles, each with a diameter of 15cm. Prick all over with a fork and lay them on oiled baking sheets.
Spread the basil and tomato puree mixture over the circles, using a brush, leaving a 1cm border all the way round the edges.
Set the oven to 230°C/gas 8. Slice the tomatoes as thinly as you can and discard the seeds and juice.
Arrange the tomato rings on the pastry and season with salt, freshly ground black pepper and a sprinkling of caster sugar. Scatter over the thyme leaves.
Bake for 5 minutes and then brush the tarts generously with olive oil. Return them to the oven for a further 5-8 minutes, until golden brown. Scatter with freshly torn basil and serve immediately.⏱ 13 min