Baked Pasta with Sauce and Mozzarella

This is one of those dishes that always looks super nice on Instagram, with those mozzarella slices stretching in the air. That's what I wanted to do too, but reality hit me - the mozzarella sunk in, and when I tried to fish it out, everything got messed up and turned into a uniform sauce.
Nevertheless, a good sauce. It's a sauce based on celery, onions, and tomatoes, but not passata, just chopped ones, with the addition of even fresh tomatoes. A good addition to pasta, and the leftovers from the pan, which should be served in (so it doesn't fall apart even more), can be picked up with a heel of bread.