Fry with a little oilve oil in a large stock pot for about 5-10 minutes over medium heat to soften up the vegetables.
Add the stock, most of the mint, and all of the pesto. Bring to a boil and let simmer for about 5 minutes.
Remove from the heat and carefully blitz in a food processor in batches or use a hand blender to make a thick soup.
Return to the pot and stir in the mascarpone along with a hefty dash of salt and dried rosemary. Serve with a sprinkling of Parmesan, the remaining mint and an extra dollop of mascarpone.
Notes
The recipe that inspired this used ricotta rather than mascarpone. I’ve tried both and I prefer the creamier finish of the mascarpone.
I would encourage you to experiment with different pestos – my favorite variation of this soup was with a cashew and basil pesto.
This soup is great for warmer weather, but you can carry it into the colder months too. Perhaps consider leaving out the mint and substituting a little chili instead.
Recipe by OntheFly Recipes at https://www.ontheflyrecipes.com/2015/11/zucchini-soup/