Cook spaghetti according to package
In a large pot, sauté the onions until golden brown. Add in the marinara and teriyaki and bring to a very low simmer.
To make the meatballs, in a large bowl mix together the onions, beef, salt, and pepper.
In a small bowl, crumble the bread into the milk and let it absorb the liquid.
Pour the whole mixture into the meat mixture and blend together until incorporated. Roll out meatballs in the size of a golf ball or use a cookie scoop and then place them into sauce. Keep mixing around very gently to completely submerge in the sauce.
Let simmer 30-40 minutes.
Serve overcooked spaghetti and enjoy!