Step 1: Prepare the Aromatics : Char the onion and ginger: Place them under the broiler or over an open flame until slightly blackened. This adds smoky depth to your broth.
Step 2: Assemble the Broth : Add beef bones, brisket, charred onion, ginger, spices, fish sauce, soy sauce, salt, sugar, and water to your slow cooker .Cover and cook on Low for 8–10 hours (or High for 5–6 hours).
Step 3: Strain the Broth : Once done, remove the brisket and set aside to slice later. Strain the broth through a fine mesh sieve or cheesecloth to remove solids. Skim off excess fat if desired.
Step 4: Cook the Rice Noodles : Prepare the rice noodles according to package instructions. Drain and rinse under cold water to prevent sticking.
Step 5: Assemble the Pho Bowls : Divide the noodles among bowls. Add thinly sliced raw beef and cooked brisket slices on top. Pour the hot broth over the beef to cook it instantly. Add your desired toppings: bean sprouts, basil, cilantro, onions, lime, chili, and sauces.