First of all, scrape away the seeds and the fibrous parts of your pumpkin wedge. (Don't discard the seeds. You can use them for other dishes as they are packed with nutrients.)
Now cut the skin away from your pumpkin and cut the pumpkin flesh into large cubes (around 3 cms) or thick slices until you have around 400 grams.
Add the pumpkin to a pan and smother with the sugar, making sure each piece is covered and then cover the pan with a lid.
Leave for 6-8 hours (or overnight) until your pumpkin pieces are sitting in a syrup.
Place your pan on the hob and gently heat on a medium setting.
As the hot syrup starts to bubble, keep basting your pumpkin pieces with it.
After around 10 minutes, test your pumpkin to see if it has softened. If not, keep simmering until it is soft but still firmly holding its shape.
Remove from the heat and allow to cool before refrigerating for an hour or so.
When it's time to serve, arrange your pumpkin dessert pieces onto a serving plate, drizzle with the tahini and top with the roughly smashed walnuts.
Serve as sweet nibbles to share after a main meal or as a sweet snack between meals.