Wash the pumpkin and cut in half. Place the pumpkin halves with the cut surface facing down on a baking tray, add a little cold water and place in the hot oven for 40 minutes.
In the meantime, mix the butter with the herbs, the finely chopped onion, the pressed garlic clove and the lemon juice until it is nice and creamy.
When the pumpkin is done, remove the seeds and loosen the pulp with a fork, this makes wonderful spaghetti-like threads (hence the name). Leave the pulp in the pumpkin and add a dollop of butter. Sprinkle with the parmesan and serve immediately.