Soak Italian bread in milk until saturated.

Squeeze out excess milk from the bread.

Combine ground beef, pork, and veal in a bowl.

In a separate bowl, whisk together Parmesan, Italian-flavored breadcrumbs, parsley, salt, pepper, eggs, and garlic.

Add the cheese mixture and soaked bread to the meat mixture.

Mix all ingredients well to combine.

Form the mixture into meatballs.

Heat olive oil in a large skillet over medium-high heat.

Fry the meatballs in batches until browned and cooked through.

Remove meatballs from the skillet and set aside.

Wipe out the skillet.

Heat olive oil in the skillet over medium heat.

Add garlic and onion to the skillet and cook until lightly browned.

Add tomato paste to the skillet.

Fill the tomato paste can with red wine and pour into the skillet.

Add crushed tomatoes to the skillet.

Fill the tomato can with water and add it to the skillet.

Add parsley, salt, and pepper to the skillet.

Stir well and bring the sauce to a boil.

Reduce heat to low, cover, and simmer for 1 hour and 15 minutes, stirring occasionally, until slightly thickened.

In the skillet used for meatballs, heat olive oil over medium-high heat.

Brown the sausages in batches.

Add the meatballs and sausages to the sauce.

Simmer for 25 minutes, stirring occasionally.

Cook spaghetti according to package instructions.

Drain the spaghetti.

Transfer the spaghetti to a large bowl.

Add a few spoonfuls of the sauce (without meatballs and sausages) to the spaghetti.

Mix to lightly coat the spaghetti.

Transfer the remaining sauce with meatballs and sausages to a platter.

Serve the spaghetti alongside the sauce.