Sear the diced tenderloin on all sides and let sit. Fry the potatoes until golden brown and set aside. Sauté the onions separately. Heat the red wine sauce.
Red Wine Sauce
Put all the ingredients into a pot. Reduce to a 1/3 of the liquid on low heat. Add the butter right before serving.
To serve, drizzle the sauce around the meat and potatoes mixed with the onions. Right before serving, separate the eggs. Place the egg yolks back into the shell. Place the egg on top of the meat and potatoes.