Start by slicing the steak as thin as you can. Make sure you slice against the grain (see photos). Ideally you want 1/8 inch slices that are about 2-3 inches long.

Place the sliced meat in a bowl and mix in cornstarch, pepper, and soy sauce. Let sit for 10 minutes while you chop up the veggies.

Thinly slice the onions. Mince the garlic. Mince the ginger.

Place a bowl or dish with a lid next to the stove to hold the meat once it's cooked.

Heat a large soup pot over medium-high heat. Add 1 tablespoon olive oil.

When the oil is shimmering, add half (or a third) of the marinated meat in a single layer over the bottom of the pot. Don't crowd the meat! You want it to brown, not steam. Cook without stirring for 1 minute.

Stir and flip the meat. Cook for another 30 to 60 seconds, until the meat is barely cooked and very tender.

Transfer the meat to the dish with a lid. Drain any liquid into the dish.

Heat the next tablespoon of olive oil. Repeat process with the remaining meat, in another couple batches if you can't fit it in one. Transfer meat and juices to dish and cover.

With the burner still on medium high heat, add the onion, garlic, and ginger to the pot. Add 1/2 cup of beef broth and salt. Scrape up those delicious brown bits on the bottom of the pot.

Let onion mixture cook for 3 minutes until slightly softened and very fragrant.

Add broccoli and remaining 7 and 1/2 cups beef broth. Turn the heat up to high.

When the soup boils, stir in the oyster sauce and chili paste.

Simmer broccoli for 2 minutes, until barely softened and still crisp.

Adjust the salt, pepper, and chili paste as desired.

Remove from heat and add the cooked meat and any juices. Stir and serve right away.