Place the garlic, celery and brown onion into your Thermomix bowl and mix for 6 seconds, speed 7 to grate.
Scrape down the sides of your bowl and add the sweet potato, zucchini and carrots and mix for 5 seconds, speed 6 to grate. If you would like your veggies grated finer, mix for a further 3 seconds, speed 6.
Scrape down the sides of your Thermomix bowl and add the olive oil. Cook fo 4 minutes, varoma, speed 2 with the MC on.
Scrape down the sides of your Thermomix bowl and add the crushed tomatoes, vegetable stock and water. Place the simmering basket on top of your Thermomix (or use the splash guard if you are cooking in a TM6) and cook for 12 minutes, 100 degrees, speed 2.
After 12 minutes scrape down the sides of your Thermomix bowl and check the consistency of the sauce - if you would like it 'thicker' you can cook for a further 5 minutes, 100 degrees, speed 2 with the splash guard/simmering basket on.
Serve with freshly cooked pasta and parmesan cheese.