Boil a pot of water and cook the chicken, cut into pieces, for 20 minutes, then remove from the water and let it cool.
Meanwhile, prepare the shortcrust pastry by mixing all the ingredients without overkneading the dough, then wrap it in plastic wrap and put it in the refrigerator for an hour.
Bring the milk to a boil in a large saucepan, mix the sugar, a pinch of salt, flour, a pinch of cinnamon and the yolks in a bowl, add the hot milk to the mixture in three times, mixing with the whisk. Then pour the mixture back into the saucepan, heat over low heat, continuing to stir with the whisk, remove from the heat as soon as the cream begins to thicken and pour it back into a bowl to cool quickly.
Cut the ham and half of the chicken into strips. Remove any soil from the mushrooms and slice them. Remove the casing from the sausage and crumble it with your hands. Roughly cut the chicken livers.
Put a little extra virgin olive oil in a pan over medium heat, add the livers, sausage, mushrooms and chicken strips, cook for 2-3 minutes pay attention do not stick to the pan. Add half of the meat sauce and cook for 10 minutes over low heat. At the end add the strips of cooked ham. Salt and pepper to taste.
Blanch the peas for 2-3 minutes, cool them with running water and drain. Salt them lightly. Reserve some for decoration.
Put two eggs in a saucepan in cold water and cook them for 9-10 minutes after boiling, cool with running water. Then remove the shell and slice the hard-boiled eggs.
Mix the remaining coarsely chopped chicken in the mixer, mix with the grated Parmigiano and one egg, salt and pepper to taste. Obtain small meatballs, a maximum of 2 cm in diameter. Fry them in abundant extra virgin olive oil, turning them frequently.
Bring a pot of salted water to the boil, cook the macaroni for 3/4 of the cooking time indicated on the package, drain them well and put them in a bowl with the remaining meat sauce.
Turn on the oven and bring it to 200 ° C (400 ° F).
Remove the dough from the refrigerator, divide it into equal parts, according to the number of portions. Flour the work surface, take a portion of shortcrust pastry, divide it into a smaller part, about 1/4, which will serve to close the timbale at the top and a larger one, about 3/4 which will serve for the base and the side walls. Using a rolling pin, flatten the two shortcrust pastry disks. Butter a ramekin and insert the larger shortcrust pastry making it adhere well to the walls.
Drain and add some macaroni, some meatballs, a few slices of boiled egg, a spoonful of the mixture of meat and mushrooms, a few peas, the custard, letting it pour into the other ingredients. Finish with a few slices of truffle. Close the timbale with the other shortcrust pastry, sealing the edges with a fork, make a few holes with a fork on the top to let the steam out during cooking. Brush with a little egg.
Repeat the previous two steps for all portions to be made.
Bake at half height and cook for 30-40 minutes.
Heat the peas left in the microwave for 10-20 seconds, pour a little gravy on the flat plate and spread it, remove the timbale from the ramekin and place it in the center on the plate, put some peas as decoration, repeat the operation for the other timbales, serve hot.