Set aside about a third of the cream cheese package, then mix the ingredients for the filling and season with nutmeg, salt and lemon pepper. Now put the filling in a piping bag or in a plastic bag with the corner cut off and fill the cannelloni with it. Be careful that there are no air bubbles inside the pasta tubes, if necessary help with a spoon handle. Put the cannelloni in a greased baking dish.
Sweat the onion cubes in a little fat, add the mushrooms and shrimps and sauté briefly. Deglaze with sherry and bring to the boil. Then add the fish stock and let it reduce for about 10 minutes. Add the remaining cream cheese, season with salt, pepper and tarragon.
If you like, you can add a little milk, then it will be creamier, or bind with a little sauce thickener, but for me it is enough without.
Pour the sauce over the cannelloni, also place the mozzarella cubes and cherry tomato halves on top. Bake for half an hour until the noodles are soft.