Ketchup most certainly has a place in every kitchen, but I love tomato jam even more, for a couple of reasons: It’s not as sweet and it’s a cinch to make in the oven. I flavor my basic jam with just some red wine vinegar and spicy red pepper flakes, though sometimes I add fennel or mustard seeds to boost the flavor and lend a little more texture. As you’ll see, it’s easy to customize the recipe to your own tastes.
Preheat the oven to 425°F.
In a 9 by 13-inch ceramic baking dish, combine all the ingredients and mix well. Roast, stirring two or three times, for about 1 hour, until the tomatoes break down and are coated in a light syrup.
Using a potato masher or fork, smash the tomato mixture into a coarse paste. Let the jam cool completely, then transfer to a 1-pint glass jar with a tight-fitting lid. Refrigerate until chilled.
The tomato jam can be refrigerated for up to 3 weeks.