Boil or steam half of the broccoli until it's slightly tender. Cook the other half a bit longer. Once the second half is well-cooked, blend it in a blender with 4 tablespoons of cottage cheese, 2 tablespoon of water, and adjust the salt. The consistency should be creamy.
In a baking dish or ramekin, place a layer of the cottage cheese cream. Add, in a single layer, your slightly tender broccoli on top.
Cover the broccoli with the creamy mixture. Sprinkle Parmesan or Mozzarela on the top.
Preheat the oven to 200 degrees Celsius (392 degrees Fahrenheit). Bake the gratin until it turns golden brown.