In a medium saucepan over medium heat, cook onion in olive oil until soft, about 5 min

Add garlic and oregano, stir.

Add carrots, veggies, tomato paste and stock. Stir and bring to a boil.

Add pasta. Cover and cook for 10-25 min until carrots are tender. You can overcook the pasta in this case, since it will be puréed.

Once all the veggies are tender, remove from heat and stir in ricotta cheese and Parmesan. Allow to cool and puree until smooth, adding liquid if necessary.