Portuguese steak is a preparation of a fairly thin cut of meat, most commonly fillet of rump steak. Portuguese steak is highly flavorful with a bit of spice, and it is an excellent way to flavor an economical cut of meat. Cooked Portuguese steak is commonly served with potatoes on its own or topped with an egg, but it can also be used for making sandwiches. Portuguese steak will keep in the refrigerator for up to 72 hours for later use.
Combine the onion, garlic, bay leaf, red chili flakes, red wine and freshly ground black pepper in a small mixing bowl. Toss the mixture with a pair of tongs or two wooden spoons to fully combine them.
Place the rump steak fillet in a clean, food safe container and pour the marinating mixture from the small mixing bowl over the top. Cover the container and gently shake it. Place the container in the refrigerator for eight hours or overnight.
Heat a large sauté pan or nonstick skillet over high heat on the stovetop for two minutes or until it is just smoking. Meanwhile, remove the marinated rump steak fillet from the marinade and place it on a plate.
Put the marinated rump steak fillet in the hot sauté pan or nonstick skillet and cook it for one minute on the first side. Flip the rump steak fillet over and cook it for an additional 90 seconds on the other side.
Remove the meat from the hot sauté pan and transfer it to a clean plate. Allow the cooked rump steak fillet to rest for five minutes before slicing or serving it so the natural juices can redistribute throughout the meat.