Lightly oil 4 individual tartlet tins, each about 10 cm (4 inches) in diameter. Brush a sheet of filo pastry with a little of the oil. Cut in half, then across into 4 equal-sized squares and use to line one of the tins. Repeat with the remaining pastry sheets. Brush any remaining oil over the pastry in the tins.
Put 5 tomato halves in the bottom of each tartlet. Top with the goats' cheese, then add the remaining tomato halves and pine nuts. Sprinkle with the thyme leaves and season well with salt and pepper.
Bake the tartlets in a preheated oven, 200°C (400°F), Gas Mark 6, for 10–12 minutes or until the pastry is crisp and golden. Serve hot with a leafy green salad.