sauté onion and garlic in oil until beginning to soften (around 2 minutes)

add the carrots and sauté for 4 minutes

add the red pepper, zucchini and sauté until beginning to soften (2-3 minutes)

add butter, Leek, mushrooms and cook for 5 minutes

add tomato, tomato puree, basil, parsley, salt, sugar, pepper and simmer cover for 15 minutes

blend in food processor

press through a sieve and stir in the mascarpone cheese

meanwhile cook the pasta and drain and toss with tomato sauce