Pre-heat the oven to 200°C.
Dust a work surface with a little plain flour and roll the pastry out on it until it is about ½cm thick. Use a circular cookie cutter to stamp out 4 rounds of pastry roughly 5cm in diameter. Arrange them on a lined baking tray and brush with some of the beaten egg.
Bake for 6-8 minutes until golden risen. Meanwhile, pre-heat the grill to hot. Remove the rounds of pastry when they are ready and sit a disc of goat's cheese on top of each. Grill for 2-3 minutes until the tops just start to colour, then remove and spoon a teaspoon of honey on top of each piece of goat's cheese.
Divide the baby spinach leaves between 4 serving plates then sit the puff pastry tartlets on top. Garnish with a sprig of thyme before serving.