Slice the buns in half and lightly toast them in a dry skillet over medium heat until golden brown, about 2 minutes. Spread a generous layer of mayonnaise on the inside of both the top and bottom halves of each bun.

In a large skillet over medium heat, cook the bacon slices until crisp and golden, about 5 to 7 minutes. Transfer the cooked bacon to a plate lined with paper towels to drain, leaving the rendered bacon fat in the skillet.

Crack the eggs into the same skillet with the reserved bacon fat and fry them over medium heat until the whites are fully set but the yolks are still runny, about 3 minutes. Carefully remove the fried eggs and set them aside on a warm plate.

Season the thinly sliced steak evenly with salt and pepper. Increase the skillet heat to medium-high, add a drizzle of olive oil if the pan is dry, and sear the steak for 1 to 2 minutes per side until perfectly browned.

Place a slice of ham and a slice of mozzarella cheese on top of each cooked steak portion in the pan. Cover the skillet with a lid for about 30 seconds, or until the mozzarella is beautifully melted and bubbly.

To assemble, layer the bottom buns with the shredded lettuce, tomato slices, and green olives. Carefully transfer the cheesy steak and ham layer onto the vegetables, then top with the crispy bacon and the fried egg.

Close the sandwich with the top bun, pressing down very lightly so the egg yolk adds richness to the fillings. Serve immediately with a side of crispy french fries for an authentic Uruguayan dining experience.