Take 3 lbs. of ribeye steak. You can also use sirloin steak, which is a cheaper cut. If your steak is thawed and at refrigerator temperature, place in the freezer for about 2 hours. If your steak is completely frozen, place it in the fridge overnight, about 8 to 10 hours, to soften a bit but still be very firm. When it's firm (but not frozen), slice them very thinly against the grain. Once the steak is sliced, let it finish thawing in the fridge.

Take a large non-reactive bowl like glass or stainless steel. Add in 1/3 cup of soy sauce, juice from 1 lemon, juice from 1 lime, half a head of garlic (about 6 cloves) finely minced, 1 packed tbsp of dark brown sugar, and 1 tsp of ground black pepper. Mix this together thoroughly till well combined.

Add in the thinly sliced pieces of ribeye steak, and gently mix them into the marinade, being careful not to tear the pieces of beef. Cover the bowl with plastic wrap and leave the steak to marinate in the fridge for a minimum of 2 hours, preferably overnight (up to 24 hours).

The following day, take the beef out of the fridge. Taking a handful of beef at a time, squeeze off as much marinade juice off the beef and into a new bowl, then lay the strips of beef out flat on a tray to air dry. The less moisture on the beef, the better they will caramelize when cooked. Save the bowl of marinade that's been squeezed off the beef, and add in any leftover marinade from the original marination bowl. Set these aside.

Take 2 sweet onions and slice each onion into 4 thick rounds, making sure not to let the rings separate. You should have a total of 8 thick rounds.

In a large skillet, add in 3 tbsp of coconut oil and heat over high heat. When the oil is very hot, add in the rounds of onions with the narrower tapered sides down, since the narrower tapered side is the side we want to brown. Do your best to prevent the rounds from separating, and brown one side in the hot oil for 3 to 4 minutes. Browning one side of the onions adds a nice caramelized flavor but still keeps the crunchiness in the classic bistek tagalog. It also imbues the oil with the delicious flavor of onions. After 3 to 4 minutes, use a spatula to remove the onions from the pan, still trying your best to keep the rounds whole (it's okay if they come apart), and set them aside.

In the same oil at the onions were fried in, let the oil get extremely hot again, almost smoking, and in batches, add in the thin strips of marinated ribeye. Only add enough pieces for a single layer in the pan. Cook each batch for 30 seconds per side. Remove the beef and set aside to cool as you cook the next batch. Do this for all the marinated beef.

When all the beef has been cooked, let the leftover oil get very hot again. When the oil is hot, add in the remaining half a head of garlic (about 6 cloves) that are finely minced, and sauté for 1 minute, till the garlic is browned and fragrant. Deglaze the pan and scrape up as much of the browned bits at the bottom as you can.

Add in 1 1/2 cups of low-sodium beef stock, the leftover marinade that was saved, 2 tbsp of soy sauce, juice from 1 lemon, 1 packed tbsp of dark brown sugar, and 1/2 tsp of ground black pepper. Mix this till well combined. When it starts to simmer, let it cook down for 5 minutes.

While the sauce is cooking down for 5 minutes, in a small mixing bowl, whisk 3 tbsp of cornstarch in 3 tbsp of water. After 5 minutes of boiling down, add in the cornstarch mixture into the sauce, and mix it in till well combined. This will immediately thicken up the sauce. Turn off the heat.

Add the cooked beef and browned onion rounds into the sauce, and fold them in till all the pieces of beef and onions are coated in the sauce. At this point, try to separate the onion rounds while folding everything together.

Serve over freshly steamed jasmine rice and garnish with some sliced scallions. Enjoy!