Firstly, peel the pumpkin, scoop out the insides and then finally cube the remainders.
Pre-heat the oven to 180°C.
Pour 40g of olive oil into the bottom of a large baking or roasting dish (I actually split it between 2 dishes), then add the cubed pumpkin into the dish. Sprinkle a further 35g of olive oil over the top of the pumpkin. Now place the baking dish into the oven and roast the pumpkin for 30 minutes.
Whilst the pumpkin is in the oven add the remaining olive oil, butter, garlic button and onions in a very large soup pan. Cook on a low heat to allow to onions to slightly golden and start to sweat. As the onions are cooking finely chop the chillies and crush the garlic.
Now add in the crushed garlic, chopped chillies, cayenne pepper and a dash of salt and pepper. Make sure you are stirring regularly.
Once the pumpkin has finished roasting in the oven add it the pan and leave to simmer on a low heat for 5-10 minutes.
Add in the crushed coriander.
Using a handheld stick blender to liquidize the soup.
It's worth trying a spoonful at this stage to see if you want to add any more spices to it.
You're now ready to either serve or save for a later date!