Taiwanese Beef Noodle Soup

Ingredient:

• 6 tablespoons neutral cooking oil (such as vegetable oil), divided
• 2 pounds boneless beef shank, sliced into 1/2-inch-thick rounds or 2 pounds oxtails (about 3 large)
• 6 cloves garlic
• 2 large scallions, cut into 1-inch pieces (about 1/2 cup)
• 2 small fresh red chiles (such as Thai chiles) (optional)
• 1 two-inch piece fresh ginger, peeled and sliced into coins (about 2 tablespoons)
• 1 tablespoon rock sugar or granulated sugar
• 1 tablespoon doubanjiang (Chinese chili bean sauce), or substitute with gochujang
• 2 plum tomatoes (about 4 1/2 ounces each), chopped (about 2 cups)
• 1 cup miju (Taiwanese rice wine), or Chinese rice wine for cooking (such as Shaoxing) or dry sake
• 10 cups water
• 1/4 cup light soy sauce, plus more to taste
• 2 tablespoons dark soy sauce (if unavailable, increase light soy sauce to 1/2 cup)
• 1 teaspoon kosher salt
• 1/2 teaspoon Chinese five spice
• 1 tablespoon Sichuan peppercorns
• 2 whole star anise
• 1 pound cooked Asian wheat noodles (preferably thick and flat varieties)
• Serving options: chopped green scallions, pickled Chinese mustard greens, drizzle of chile crisp or chile oil