Sauce: Melt the butter over low heat, add the flour and stir while pouring hot milk with cream, avoiding the appearance of lumps. After the appearance of a homogeneous mass, add nutmeg, salt and remove from heat. Stuffing: Fry the onion in olive oil, add meat. Pre-boil cannelloni in salt water, about 4 minutes. Fill the bottom of the mold with 5 mm sauce. Fill cannelloni with a teaspoon filling and lay the first layer, which is sprinkled with parmesan.
Then we put the second layer, fill the form with sauce and sprinkle with the remaining cheese. We put in the oven for 20 minutes at a temperature of 190 degrees.