Soak the beef marrow bones in cold water for 4-5 hours to remove all the blood, changing the water every 1-2 hours. This step is essential for a clear broth. Note that marrow bones are the first choice for pho broth because they provide the characteristic sweetness. After soaking, rinse thoroughly, add water, and bring the bones to a boil to remove impurities. Drain and rinse the bones again, then add fresh water and start simmering. My pot is 6.5 liters, and I fill it to the top.

Wash all ingredients and let them dry, except for the dried sea worms, which should not be washed but have their ends trimmed. Arrange the ingredients in an air fryer and roast at 300°F for 10 minutes. After 10 minutes, remove the sea worms, cinnamon, cardamom, star anise, and cilantro roots. Continue roasting the ginger, onion, and shallots for another 10 minutes.

Once the ingredients are roasted and fragrant, place them in a cloth bag and add to the pot of broth, or add them directly to the pot and simmer for 4-5 hours. Add 1/2 tablespoon of coarse salt to the pot. When simmering bones, even pork bones, coarse salt helps extract more sweetness.

While waiting for the broth, prepare the vegetables and slice the meat. Marinate the beef brisket with 1 tablespoon oyster sauce, 1 tablespoon fish sauce, 1/2 tablespoon cooking oil, and 1/2 tablespoon ground pepper. Keep in the refrigerator until ready to eat. Place the fresh pho noodles on a separate plate.

To keep the broth clear, you can leave the lid off while simmering. Once the simmering time is up, start seasoning the broth. Add 5-7 pieces of rock sugar and 2 tablespoons of seasoning salt. Just before serving, add 1 tablespoon of good fish sauce for extra flavor. Boil 3 liters of water in a small pot, then briefly blanch the pho noodles, drain, and place in bowls. You can also briefly blanch the beef in the broth if you prefer it cooked. Then, finely chop the green onions, cilantro, and bean sprouts, and arrange them in the bowls, pouring hot broth over the top.

You can sprinkle finely sliced green onions on top for a more attractive presentation. And that's how you make Hanoi-style beef pho. Enjoy and good luck!