Arrange each beef slice between two parchment paper or cling wrap and with a meat mallet, pound to about ½-inch thick (or thinner).
Repeat with remaining beef slices. Trim sides of meat to shape it as close to a rectangle.
In a bowl, combine beef, lemon juice, soy sauce and pepper to taste.
Marinate for about 30 minutes.
Drain beef from marinade, squeezing any excess liquid and reserving marinade.
Lay beef on a flat work surface arranges strips of carrots, hot dogs, pickles, and eggs lengthwise over the meat.
Gently gather the end of beef upwards and roll neatly into a log, enclosing the filling.
With kitchen twine, tie beef roulades snugly at both ends and center to fully secure.
Lightly dredge with flour.
Heat oil in a wide, heavy-bottomed pan. Gently add the beef roll and lightly brown on all sides. Remove from pan and drain on paper towels.
Discard oil from skillet except for about 1 tablespoon.
Add onions and garlic and cook until browned.
Add reserved marinade and bring to a boil, scraping sides to deglaze a pan.
Add tomato sauce and beef broth.
Add bay leaf. Season with salt and pepper to taste.
Bring to a boil. Gently add beef rolls in a single layer. Lower heat, cover and cook for about 45 minutes to 1 hour or until beef is tender.
Remove beef rolls from pan and allow to stand for about 3 to 5 minutes.
Slice into 1-inch thick rounds and arrange slices on serving platter. Keep warm.
Add liver spread into the sauce and stir until dissolved.
Continue to cook for about 5 minutes or until sauce is thickened.
Pour sauce over morcon slices.
Serve