Char the ginger and shallots until fragrant. Toast the star anise and cinnamon stick until aromatic. Place all of these into a spice bag or mesh pouch.

Boil the whole chicken for sweeter meat. If your pot is small, cut the chicken into quarters for easier boiling. Bring water to a boil, blanch the chicken to remove impurities, then drain and rinse the chicken.

Return the chicken to the pot, add 1 onion, and place the spice bag on top. Add 5 bowls of water (about 10 cups/2.4 liters), then bring to a gentle boil and skim off any foam. Season with 3 tablespoons chicken bouillon powder, 2 teaspoons salt, and 1 teaspoon rock sugar. Lower the heat to medium-low and simmer the chicken for 20 minutes. Turn off the heat, cover, and let the chicken sit in the pot for another 10 minutes before removing it.

Once the chicken is cooked, transfer it to a bowl of ice water to firm up the skin and keep the meat white. Shred or slice the meat into bite-sized pieces. Return the bones to the pot and simmer on low heat for 1–2 more hours to extract more flavor from the bones.

Once the chicken meat has cooled, shred or slice it into bite-sized pieces.

I like to add a little of the chicken meat back into the pot to make it extra tender for kids.

This chicken was quite fatty, so before boiling, I removed the fat from under the skin to render chicken fat. The crispy chicken skin can be tossed with fish sauce and garlic as a snack or saved for braising fish:
https://cookpad.wasmer.app/vn/r/17044627

Thinly slice the onion and finely chop the green onions. Southern-style pho is served with blanched bean sprouts and herbs on the side.