Peel, deseed and slice the butternut squash thinly.
Chop up garlic and rosemary and cook in olive oil in a heavy bottomed pan over low heat for 1 minute. Make sure they don't take on any colour.
Add the butternut squash, stock, bring to a boil, then lower the heat and cover with a lid. Simmer for 20 minutes until butternut squash is very soft.
Start cooking gnocchi according to package directions 10 minutes before the sauce is done.
Slice the chorizo and cut into strips, fry with no additional oil for about 1 minute over low heat. Watch carefully as it burns quickly.
When the butternut squash is cooked transfer the chunky sauce into a food processor and bled until smooth and silky, then return it to the pan.
Taste the sauce and stir in grated parmesan cheese, then add salt if necessary (your stock already has salt so be careful not to over-salt).
Strain the gnocchi while reserving 1/2 cup of the cooking liquid. Add the gnocchi to the sauce with a splash of reserved water to thin out the sauce if too thick.
Serve topped with fried chorizo or bacon and freshly grated parmesan cheese.