Enjoy caprese mac and cheese, a summer indulgence to swoon over, starring hand torn fresh mozzarella, ripe tomatoes and ribbons of basil.
Preheat the oven to 375 degrees F. Bring a pot of salted water to a boil; add the pasta and cook until al dente. Drain the pasta.
Melt the butter in a large saucepan over medium heat. Whisk in the flour and cook, whisking constantly for about 2 minutes, then slowly whisk in the milk. Add the salt and nutmeg and simmer, whisking occasionally, until thick, about 8-10 minutes.
Stir in 1 1/2 cups cheddar, ¾ cup Gruyere and ¾ cup Fontina until melted. Add the pasta, half of fresh mozzarella and half of tomatoes and stir until incorporated with cheese sauce. Add the pasta mixture to a buttered 2-quart baking dish or 8 buttered ramekins and top with the remaining cheeses and tomatoes.
Sprinkle with panko and bake for about 20 minutes. After baking, top with ¼ cup chopped basil.
Store leftovers in an airtight container and reheat in the microwave.