Preheat the oven to 200˚C, gas mark 6.
Roll the puff pastry out on a clean floured surface to a 20cm x 30cm rectangle about 5mm thick.
Prick the centre of the pastry with a fork, leaving a 1cm border. Bake in the preheated oven for 10 minutes until just cooked but not golden.
Remove from the oven and allow to cool.
Mix the crème fraîche, Parmesan and garlic, and season well.
Spread the crème fraîche mixture in the centre of the cooled tart then arrange the vegetables on top in sections. Season well, drizzle with the olive oil and return to the oven.
Bake for 20-30 minutes or until the tart is golden brown and the vegetables are cooked.