Try this for size - this is off the top of me own melon, so I apologise if it goes wrong...
Get a whole load of tomatoes, plunge in boiling water, then cold water, and peel, and chop up finely.
Soften a chopped onion and a crushed clove of garlic in some butter and oil, and add a pinch of dried herbs, a teaspoon of sugar, and a small splash of vinegar.
Throw in the tomatoes, and lower the heat til barely simmering. Cover, and cook very slowly until the tomatoes have disintegrated.
Wallop in a load of tomato puree and check the seasoning, then blitz in a mixer until smooth.
Won't be the same as the real McCoy, but just might be nicer? You could also used chopped tinned tomatoes.
Good for you madness, hope you get one that suits. Kids do love the stuff and so the reduction in sugar and salt if you make your own will probably be quite substantial in the long run.
*It is not necessary to understand things in order to argue about them. -- Pierre De Beaumarchais
