Preheat the oven to 180C/350F/Gas 4.
Rub the pork fillet with olive oil, salt and freshly ground black pepper. Place onto a baking tray and place into the oven to roast for 8-10 minutes, or until completely cooked through.
Remove the pork from the oven and carve into slices. Return to the roasting tray and add the melted butter, thyme and sesame seeds. Stir to combine with the pan juices.
For the pan-fried courgettes, heat the olive oil in a frying pan over a medium heat. Add the sliced courgettes, salt and freshly ground black pepper and pan-fry until the courgettes are golden-brown all over.
To serve, place the courgettes onto a serving plate. Top with the pork and pour over any juices from the pan.