Found this recipe in Guardian Weekend. It was quite easy to make and it was a great base for a pasta sauce. Only problem is that you need to buy and carry home a lot of tomatoes. 😉
Two kilos of tomatoes fill up two oven trays so if you want to do more than 1 litre you need more trays.
Don’t worry if the sauce looks to watery, it is easy to reduce in the pan.
Roast sieved tomatoes Here’s the basic procedure, but do vary the amounts of garlic and herbs to suit your own taste. Makes about a litre.At least 2kg ripe, full-flavoured tomatoes – use different varieties and a mixture of sizes, all cut in half2-3 garlic cloves, finely chopped2 tbsp olive oilSalt and freshly ground black pepperA few sprigs fresh thyme and marjoram (optional, but preferable)Preheat the oven to 180C/350F/gas mark 4. Arrange the tomato halves – tightly packed but not on top of each other – in an ovenproof dish. Mix the garlic with the oil and trickle evenly over the tomatoes. Season lightly with salt and pepper, and throw in the herbs, if using.Roast for 45-60 minutes, until the tomatoes are soft, pulpy and slightly charred. Rub the mixture through a fine sieve, discard the skins and seeds, and that’s it – your sauce is ready to use.
From this article.