Pull the brisket from the Refrigerator 30 to 60 minutes before cooking to let it approach room temperature. Trim hard fat down to about a quarter inch. Apply your dry rub or salt-and-pepper blend evenly over the whole surface, pressing it in firmly. Soak Wood Chips in water for at least 30 minutes if your Smoker uses chips, or prep wood chunks and pellets per your smoker's directions. Empty the drip tray before you start. Set aside unwaxed Butcher Paper or heavy-duty Aluminum Foil for wrapping later in the cook.

Preheat your Smoker to 225–250°F and verify the temperature with a standalone Meat Thermometer. Add Wood Chips, chunks, or pellets per your smoker's instructions. Place the brisket fat side up with the point end toward the heat source. Close the smoker and avoid opening it often. Check wood and adjust vents every 45 minutes to hold 225–250°F. Rotate the brisket every 3 hours and flip if one side colors faster. Smoke uncovered until the internal temperature hits 165°F and a dark bark has formed, about 5 to 8 hours. Wrap tightly in Butcher Paper or Aluminum Foil, return to the smoker, and continue until an Instant-Read Thermometer reads 195–203°F and the meat is very tender but not falling apart, roughly 4 to 5 more hours. Total cook time is typically 8 to 12 hours. Use internal temperature and texture as your doneness cues, not the clock alone.

Char the 1 large yellow onion halved, unpeeled and 1 piece fresh ginger 3-inch piece, halved lengthwise: Set your Oven Broiler to high. Place the halved 1 large yellow onion halved, unpeeled (cut-side up) and 1 piece fresh ginger 3-inch piece, halved lengthwise on a Baking Sheet. Broil 4–6 inches from the heat for 8–10 minutes, turning once, until both are deeply charred and fragrant. This caramelization is the backbone of pho's signature smoky-sweet depth.

Toast the spices: In the clean dry Pot over medium heat, add the 4 whole star anise, 1 whole cinnamon stick, 1 tsp coriander seeds, and 1 tsp fennel seeds (if using). Toast, stirring, for 1–2 minutes until fragrant. Watch closely — they should smell wonderful but not burn.

Build the broth: Add the parboiled 2 lb beef bones rinsed, 1 lb beef brisket whole piece, charred 1 large yellow onion halved, unpeeled, and charred 1 piece fresh ginger 3-inch piece, halved lengthwise to the Pot with the toasted spices. Pour in 10 cups of 10 cups water. Bring to a boil over high heat, then immediately reduce to a gentle simmer. Skim off any remaining foam during the first 10 minutes.

Simmer low and slow: Simmer uncovered for 1.5 to 2 hours, until the 1 lb beef brisket whole piece is just tender when pierced with a chopstick or fork. Remove the 1 lb beef brisket whole piece and set aside to cool. Continue simmering the 2 lb beef bones rinsed for another 30–60 minutes to deepen the broth.

Season the broth: Stir in the 3 tbsp fish sauce plus more, 1 tsp salt plus more. Taste and adjust — the broth should be savory, lightly sweet, and deeply fragrant. Strain the broth through a Sieve into a clean Pot, discarding the solids. You should have about 8 cups of clear, golden broth. Keep it at a gentle simmer until ready to serve.

Peel and slice onions to about 1/8-inch thick — thin enough to cook quickly, thick enough to avoid scorching. Yellow or Spanish onions work best. Limit to 2 large onions per 12-inch Skillet to prevent steaming. Have your fat ready and keep a splash of water, broth, or wine nearby to deglaze if needed.

Heat a Skillet over medium to medium-high heat. Add butter, oil, or a mix and let it shimmer. Add sliced onions in large handfuls, stirring for 1–2 minutes per batch until they begin to soften — this prevents overcrowding. Once all onions are in, season with a pinch of salt. Cook over medium heat, stirring every few minutes, for 8–12 minutes total until soft, translucent, and lightly golden. To speed up softening, add 1/4 to ½ cup water or broth and cover; steam wilts the onions in a few minutes. Remove the lid once liquid evaporates and continue cooking uncovered. If the pan looks dry, deglaze with a splash of water, broth, or wine, scraping up any browned bits. Don't crank the heat — high heat burns the outside before the onions cook through.

Peel and slice onions to about 1/8-inch thick — thin enough to cook quickly, thick enough to avoid scorching. Yellow or Spanish onions work best. Limit to 2 large onions per 12-inch Skillet to prevent steaming. Have your fat ready and keep a splash of water, broth, or wine nearby to deglaze if needed.