Cook the spaghetti as directed on the packet. Place aside.
A cooking pot should be heated. Brown the bacon. Cook until the fat has rendered and the bacon has become crispy.
Remove the bacon and half of the bacon fat from the pot. Set aside the bacon. It will be added later. You can either save the bacon grease in a sealed container for later use or trash it.
In the same saucepan, heat the leftover bacon fat. Cook until the ground meat has browned.
Add the garlic and onion. Cook, stirring occasionally, until the onion is soft.
Pour in the beef stock. Let boil. Cook until the liquid has totally evaporated.
Add the mushrooms. Stir.
Insert the butter and cook until it is completely melted.
Pour 2 ¼ cups of heavy whipping cream. Stir and let boil. Set the heat to medium
Add the Parmesan cheese, salt, and black pepper to taste.
In a bowl, beat the egg yolks and then add the remaining ¼ cup heavy whipping cream. Continue to beat until all the ingredients are well blended.
Fill the pot with the egg yolk mixture. Stir constantly until the white sauce has thickened in texture.
Arrange a serving of spaghetti in a bowl and pour-in some carbonara sauce. Mix well.
Twirl the spaghetti carbonara using a fork and then transfer to a pasta bowl. Top with bacon and Parmesan cheese.
Serve. Share and enjoy!