Beef Phở

Brown the onion halves and split ginger under the oven grill or in a dry heavy pan until fragrant and lightly charred. Trim burnt patches rather than keeping bitter soot. Toast the star anise, cinnamon, cloves and coriander seeds briefly in a dry pan; do not burn them.

Cover the bones with water in a large stockpot, boil briefly, discard that water and clean the pot. Return the bones with the 5.7 l broth water, brisket, charred onion and ginger, and toasted spices. Simmer uncovered very gently for about 3 hours, skimming foam. Remove the brisket when tender; keep it hot for serving or chill promptly in a shallow container, not on the counter.

Strain the broth and discard the bones and spent aromatics. Stir in fish sauce, fine sea salt and rock sugar, tasting as you add them; add water if the broth is too concentrated. Thinly slice the cooked brisket across the grain. Keep the raw sirloin cold and separate from ready-to-eat garnishes.

Cook the rice noodles separately according to their packet and divide among bowls. Cook the sirloin separately until it reaches 63°C / 145°F and rests for 3 minutes; pouring hot broth onto raw slices is not a reliable safety check. Add both cooked beef cuts, boiling broth, scallions and coriander. Serve immediately with lime, herbs and chile.