Prepare the pumpkin, cut part into slices and leave to dry in the oven at 90° for 1h-1.30h with some sugar.
Sauté the onion in a frying pan, cut the remaining pumpkin into cubes and brown for a few minutes, stirring to keep it from sticking. Pour the vegetable broth in a small pan a little at a time until the pumpkin is cooked: it should become a soft and creamy mixture.