Cannelloni

	Pour two liters of water into a pot, add 2 teaspoons of salt, and bring to a boil. Gradually lower the cannelloni into the boiling water and cook for 3 minutes. Use a slotted spoon to remove them and transfer them to a large bowl of cold water to stop the cooking process.
	Wash the onion and slice it into rings. Wash the mushrooms and cut them into thin slices. Sauté the onion in oil for 4 minutes over high heat. Add the mushrooms and fry for another 3 minutes. Then add the whole peeled shrimp (reserve a couple for the sauce), mix well, and cook on low heat without a lid for 5 minutes.
	Transfer the prepared filling to a bowl and let it cool. Grate the cheese on a coarse grater and add it to the filling. Slightly salt it and mix thoroughly.
	Place the olives and capers in a fine sieve and rinse them with cold water. Finely chop them, add the mustard and the remaining shrimp. Whip the cream slightly and combine it with the mixture, mixing well.
	Fill a piping bag with the filling. Then, fill the cannelloni one by one with the mixture. Preheat the oven to 200 °C. Place the filled cannelloni in a baking dish and drizzle with the sauce. Put it in the oven and bake for 10 minutes. Serve immediately.