With a very sharp knife, butterfly the sirloin steak by slicing it thinly in half so that it flattens out. It will be used as a meat wrap. Season with lemon and soya sauce. Set aside.
Mix the ground pork with the sweet relish, and salt and pepper to taste.
Remove the steak from the lemon-soya sauce marinade and lay it on a flat surface like a cutting board. Reserve the marinade.
Spread the ground pork mixture over the steak. Arrange the ham, chorizo, carrot and eggs over ground pork. Roll the steak like a log until the filling is entirely covered and secure at both ends. Tie the meat roll with a string.
In a large pot, heat oil over medium heat and fry all sides of the meat roll until brown.
Add 500ml water, the bay leaves, onion, garlic, tomatoes, peppercorns and reserved lemon-soya sauce marinade. Cover and cook for 5 minutes.
Add the tomato sauce and salt and pepper to taste. Simmer for another 20 minutes over low heat.
Remove the meat roll from the sauce and cut it crosswise and arrange slices on a platter. Pour the sauce over and serve.