Last year I canned a sweet and savory tomato jam, and it came in quite handy recently when I had a craving for a caprese sandwich. Rather than buy out-of-season tomatoes, I used some of that jam with creamy fresh mozzarella from the local Italian shop and luckily spinach had already made its debut at the farmers' market (was still too early for basil). In fact, I often make a big batch of the spinach I use in the sandwich and keep it on hand to add to pasta or serve as a vegetable side. If you don't have a homemade tomato jam in the pantry, Katchkie Farms makes a very lovely one that can be mail ordered—and it reminds me very much of the one I'll be making once tomatoes come around again this year. —Jennifer Perillo
Heat olive oil in a small nonstick skillet over medium-low heat. Add the shallots and saute until fragrant, about 1 minute. Add the spinach and raisins and saute until raisins are plump and the spinach is wilted, about 1 to 2 minutes. Remove from heat and set aside.
Heat cast iron skillet over medium flame, or alternately preheat your panini grill.
Meanwhile, arrange two slices of bread on a countertop or cutting board. Slather an equal amount of tomato jam on each slice. Top with equal amounts of mozzarella slices. Arrange equal amounts of spinach on top of cheese. Top with remaining slices of bread.
Place sandwich into hot skillet and use a heavy-bottomed skillet or pot to weight it down, or alternately place it into your heated panini press. If using the manual stovetop method, turn the sandwich once the underside is nicely browned, return heavy-bottomed pot on top of sandwich and continue to cook until golden on other side. Serve hot.
Jennifer Perillo is the Consulting Food Editor at Working Mother magazine, and a regular a contributor to Relish Magazine and FoodNetwork.com. She shares stories about food, family and life at her blog In Jennie's Kitchen and in her debut cookbook, Homemade with Love: Simple Scratch Cooking from In Jennie's Kitchen (Running Press 2013).