Makes 8 satisfying (American-sized) bowls
For the broth:
2 medium yellow onions (about 1 pound total)
4-inch piece ginger (about 4 ounces)
5-6 pounds beef soup bones (marrow and knuckle bones)
5 star anise (40 star points total)
6 whole cloves
3-inch cinnamon stick
1 pound piece of beef chuck, rump, brisket or cross rib roast, cut into 2-by-4-inch pieces (weight after trimming)
1 1/2 tablespoons salt
4 tablespoons fish sauce
1 ounce (1-inch chunk) yellow rock sugar (duong phen; see Note)
For the bowls:
1 1/2-2 pounds small (1/8-inch wide) dried or fresh banh pho noodles (“rice sticks” or Thai chantaboon)
1/2 pound raw eye of round, sirloin, London broil or tri-tip steak, thinly sliced across the grain (1/16 inch thick; freeze for 15 minutes to make it easier to slice)
1 medium yellow onion, sliced paper-thin, left to soak for 30 minutes in a bowl of cold water
3 or 4 scallions, green part only, cut into thin rings
1/3 cup chopped cilantro (ngo)
Ground black pepper
Optional garnishes arranged on a plate and placed at the table:
Sprigs of spearmint (hung lui) and Asian/Thai basil (hung que)
Leaves of thorny cilantro (ngo gai)
Bean sprouts (about 1/2 pound)
Red hot chiles (such as Thai bird or dragon), thinly sliced
Prepare the broth:
Char onion and ginger. Use an open flame on grill or gas stove. Place onions and ginger on cooking grate and let skin burn. (If using stove, turn on exhaust fan and open a window.) After about 15 minutes, they will soften and become sweetly fragrant. Use tongs to occasionally rotate them and to grab and discard any flyaway onion skin. You do not have to blacken entire surface, just enough to slightly cook onion and ginger.
Let cool. Under warm water, remove charred onion skin; trim and discard blackened parts of root or stem ends. If ginger skin is puckered and blistered, smash ginger with flat side of knife to loosen flesh from skin. Otherwise, use sharp paring knife to remove skin, running ginger under warm water to wash off blackened bits. Set aside.
Parboil bones. Place bones in stockpot (minimum 12-quart capacity) and cover with cold water. Over high heat, bring to boil. Boil vigorously 2 to 3 minutes to allow impurities to be released. Dump bones and water into sink and rinse bones with warm water. Quickly scrub stockpot to remove any residue. Return bones to pot.
Simmer broth. Add 6 quarts water to pot, bring to boil over high heat, then lower flame to gently simmer. Use ladle to skim any scum that rises to surface. Add remaining broth ingredients and cook 1 1/2 hours. Boneless meat should be slightly chewy but not tough. When it is cooked to your liking, remove it and place in bowl of cold water for 10 minutes; this prevents the meat from drying up and turning dark as it cools. Drain the meat; cool, then refrigerate. Allow broth to continue cooking; in total, the broth should simmer 3 hours.
Strain broth through fine strainer. If desired, remove any bits of gelatinous tendon from bones to add to your pho bowl. Store tendon with cooked beef. Discard solids.
Use ladle to skim as much fat from top of broth as you like. (Cool it and refrigerate it overnight to make this task easier; reheat befofe continuing.) Taste and adjust flavor with additional salt, fish sauce and yellow rock sugar. The broth should taste slightly too strong because the noodles and other ingredients are not salted. (If you’ve gone too far, add water to dilute.) Makes about 4 quarts.