I've been looking for my recipe for some time and haven't found it. I made this back in the 1970s and it's very good. But today, at the web site below, I found a recipe for it and it sounds like the one I'm missing.
So, here's the recipe and also the site that has a great blog post with many recipes for using up tomatoes.
Tomato-Prune Jam
12 oz pitted prunes
2 lbs ripe tomatoes (4-5 medium)
Bouquet garni: 1 cinnamon stick, 3 cloves, 3 allspice berries, 2 lemon peel strips
2 tbsp lemon juice
½ c. Granulated sugar
½ c. Brown sugar
1 tbsp (ore more to taste) red wine vinegar
Cut prunes into ½” pieces. Dip tomatoes in simmering water for 30 seconds; cool in ice water bath. When cool enough to handle, slip off the skins. Force out seeds into a fine strainer and reserve juices. Coarsely chop tomatoes.
Combine prune, tomatoes, strained juices, and bouquet garni in a deep non-reactive large pot. Cover and bring to a simmer. Uncover and simmer 15 minutes stirring often. Mix will thicken and be free of standing liquid.
Stir in lemon juice, then sugars one at a time. Continue cooking for another 10 min until jam is thicks again and thermometer reads 208-210 degrees f.
Remove from heat, remove bouquet, stir in vinegar. Quickly cool a tablespoon of jam in the freezer and taste for the slightly tart finish of vinegar to balance the sweet fruits. Add more vinegar if desired. Pack into jam jars. Process in boiling water bath 10 minutes.
http://sandychatter.wordpress.com/2011/03/11/you-can-never-have-too-many-tomatoes/