We make this sauce all the time in our household and freeze it down. When you get home late and just want something quick like pasta and sauce, all we have to do is grab a pack from the freezer and we're eating in 10 minutes.
Make lots of this, double the recipe. You won't regret it.
Add the butter to a deep pan and melt. Add the carrots and fry off for a few minutes
Add the celery and onions and cook until softened. Then add the garlic and dry for another minute
Add the tomato puree and cook for a minute before adding the tins of chopped tomatoes. Give the tins a quick rinse and add the water into the pan
Add the sugar to reduce the acidity of the tomatoes and bring to a boil.
Reduce the heat to a simmer and add the bay leaves, oregano and the stock (whichever you use) and give a stir
Place a lid on the pan and leave to simmer for an hour to allow the tomatoes to break down and herbs to infuse the sauce
Remove from heat and let cool
Blast in a blender until smooth, decant into sauce bags and freeze