In a large bowl, gently and thoroughly mix the sliced steak, soy sauce, lemon or lime juice, garlic cloves, sugar, and pepper. Cover and keep in the refrigerator for 1 to 24 hours.

When ready to cook, remove the marinated steak from the refrigerator and place in a strainer over the same marinade bowl. Keep as much of the marinade that drains off as possible.

Heat an extensive carbon steel or cast-iron skillet with enough oil to coat the bottom over medium-high heat. Once it begins to smoke, add the onion slices whole and together across the pan and cook untouched for 2 minutes. They should be browned on the one side. Remove them and set them to the side. It’s essential and classic to keep that crunch.

In that same skillet, place enough marinated steak slices to cover the pan, but without touching them, sear for only 20 to 30 seconds per side or until at least browned around the edges. Set to the side on a plate and continue cooking in batches. Feel free to add as much oil as needed between searing the steak.

Add 1 to 2 teaspoons of oil to the pan, stir in the garlic over low heat, and cook until fragrant. This only takes 30 to 45 seconds.

Next, add the remaining drained marinade, soy sauce, lemon juice, sugar, beef stock, and pepper and boil over high heat for 2 to 3 minutes. At this stage, you can skim any of the beef impurities that collect at the top, but this is optional.

While boiling, you can quickly make your slurry by mixing 3 tablespoons of each cornstarch or potato starch with 3 tablespoons of water.

Add the cornstarch 1 tablespoon into the pan until the sauce is thickened.

Finish by gently folding in the cooked onions and steak.

Serve the bistek over cooked rice with the onions on top.