I found this recipe for Tomato Mozzarella Gratin (Tomaten-Mozzarella-Gratin) in a small pasta cookbook I picked up in Germany a few years ago. Lasagne noodles are broken into large pieces, then arranged with slices of tomatoes and mozzarella. After baking until the cheese is melted and the tops of the noodles are golden, the gratin is served with fresh basil leaves. I added a drizzle of balsamic reduction as a personal touch. It was not included in the original recipe, but I like the extra burst of color and flavor it provided.
I used heirloom tomatoes, but any large, ripe tomato will work well.
If you want to add the balsamic drizzle, you can make your own or I have even started to see them in the vinegar section of larger grocery stores. To make your own: whisk together 1/4 cup balsamic vinegar and 1 tablespoon honey in a small saucepan over medium heat. Once it comes to a boil, reduce heat to a simmer and cook, stirring occasionally, until the liquid has reduced by half. Once thick enough to coat a spoon and hold its shape when drizzled, remove from heat.
Tomato Mozzarella Gratin
Adapted from Die besten Ideen für Pasta
300 grams (10 1/2 ounces) Lasagne noodles
Salt to taste
1/2 cup olive oil, divided
600 grams (21 ounces) large tomatoes
250 grams (8-9 ounces) fresh mozzarella
Freshly ground black pepper to taste
1 small bunch fresh basil
Balsamic reduction for drizzling (optional)
Break the lasagne noodles into pieces (3-4 for each noodle).
Bring a large pot of salted water to a boil. Add the broken lasagne noodles and cook, stirring occasionally to keep them from sticking to the bottom. Cook until al dente, just tender. Drain and lightly toss in about 2 tablespoons olive oil.
Cut the tomato into about 1/4 inch thick slices. Cut the mozzarella in about 1/4 inch thick slices too.
Preheat oven to 425 degrees F. Grease an 8×8 inch baking dish with olive oil. Add half of the cooked lasagne noodles to the bottom of the pan. Arrange the tomato slices, noodles, and mozzarella slices at a semi-upright angle over the bed of lasagne noodles so all the parts are showing- tomato slice, noodle, mozzarella slice, noodle, until the baking dish is filled.
Drizzle with olive oil and season with salt and pepper. Bake in preheated oven until cheese is melted and the tops of the noodles are starting to turn golden, 12-15 minutes.
Sprinkle with basil leaves before serving and drizzle with balsamic reduction if desired.