To prepare the jam, combine the tomatoes and spices in a medium-size, nonreactive pan with a heavy, flat bottom. Place the pan over medium-low heat and bring the contents to a simmer. As the ingredients simmer, stir with a wooden spoon every 3–4 minutes to prevent them from sticking to the bottom of the pan. The jam has a tendency to scorch as it thickens, so watch the pot carefully and stir the contents frequently. After 30–40 minutes, the consistency of the jam should be thick and viscous, and should coat the back of the spoon. Transfer the jam to a non-reactive bowl, fold in the mint and set aside to cool. The jam can be made up to one week in advance of serving the sliders.