¼ cup reduced-sodium soy sauce, plus more to taste
1 tablespoon chile-garlic sauce (see Tip), plus more to taste
1 tablespoon minced fresh ginger
3 tablespoons cornstarch
1 tablespoon toasted sesame oil
3 cups cooked lo mein noodles (about 6 ounces dry)
1 cup sliced scallions
1Discard mushroom stems and cut the caps into ½-inch pieces. Spread the mushroom pieces in a 6-quart or larger slow cooker (see Tip). Add carrots and bamboo shoots. Cut tofu into ½-inch pieces, add to slow cooker and sprinkle with white pepper. Top with cabbage.
2Combine 4 cups water, broth, both vinegars, soy sauce, chile-garlic sauce and ginger in a bowl; add to the slow cooker.
3Cover and cook 4 hours on High or 7 to 8 hours on Low.
4Whisk the remaining ⅓ cup water, cornstarch and sesame oil in a bowl. Stir into the soup. Cover and cook on High for 20 minutes. Stir in noodles, cover and heat through for 10 minutes. Serve topped with scallions and with more soy sauce and chile-garlic sauce, if desired.
To make ahead: Prep mushrooms and vegetables; combine the liquids and ginger used in Step 2. Refrigerate separately.
Equipment: 6-quart or larger slow cooker
Tips: Look for chile-garlic sauce, a blend of ground chiles, garlic and vinegar, in the Asian section of large supermarkets. Refrigerate for up to 1 year.
For easy cleanup, try a slow-cooker liner. These heat-resistant, disposable liners fit neatly inside the insert and help prevent food from sticking to the bottom and sides of your slow cooker.