Add onion and garlic to Thermomix Bowl and chop, 3 secs/speed 5. Scrap down sides of bowl.
Add leek, tomato paste, olive oil and butter and saute 4 mins/100℃/speed 0.5/no measuring cup/simmering basket sitting on lid
Add remaining vegetables and chop 10 secs/speed 6, using the spatula through the lid hole to help. Scrape down sides of bowl and chop 5 secs/speed 6 if there still some big veggies present.
Add tin tomatoes, sugar, oregano and season. Cook 20 mins/120℃/speed 1/no measuring cup/simmering basket sitting on lid
Taste and adjust seasoning. Remove half and blend the remaining using the Blend function for 1 minute speed 8 or until a smooth paste consistency is achieved.For TM5, Blend 2 min/speed 5-8,increasing speed graduallyfrom speed 5 to speed 8 or until a smooth paste consistency is achievedTip into a container and repeat with the second portion of sauce.Use as desired.
Notes
Make sure throughout this cook you do not exceed the maximum fill line, and blend half the sauce at a time.See additional notes on storage etc in my blog feed.