Frugality with food (online and offline)

My eldest son likes to eat tomatoes the way others eat apples - straight from the refrigerator, in huge bites. Since I also like having the odd tomato around for salads and sandwiches, I usually buy a lot of tomatoes. However, last time I got some, I'd forgotten that Eldest was going to the US for the summer and our family's tomato consumption rate would be dropping drastically. As a result, I found myself with several soft-ish tomatoes which weren't compeltely spoiled, but really wouldn't do for fresh dishes. Then I remembered that there was a discussion on my local email list not long ago about how resek agvaniot (tomato paste) is full of sugar, and thus a potential stumbling block for diabetics and followers of low-carb diets. So I decided to carry out a culinary experiment and see if I could rise to the challenge of making tomato paste with no sugar that would be every bit as good as the store-bought. I think I succeeded, and I promise to share the recipe below.