How to Make It
Heat a medium skillet over medium heat. Add pork; cook 10 minutes or until crisp, stirring to crumble. Remove pork from pan with a slotted spoon; discard drippings.
Bring stock, 1 1/2 cups water, and next 5 ingredients (through fish sauce) to a boil in a Dutch oven. Add pork to pan. Reduce heat, and simmer 10 minutes. Add tofu and kimchi; reduce heat to low.
Prepare noodles according to package directions. Add noodles to pan; cook 4 minutes or until heated. Divide soup among 6 bowls; top with mushrooms, radish, onions, and serrano.
Chicken-Bok Choy Noodle Bowls: Use 3 halved baby bok choy (about 6 ounces) in place of kimchi. Omit the pork. Rub 1 pound skinless, boneless chicken thighs with the gochujang and 1 tablespoon sugar; grill over medium-high heat 4 minutes on each side. Let stand 10 minutes; cut into large dice, and place on top of stew. Serves 6 (serving size: about 1 1/3 cups soup plus garnishes) Calories 302; Fat 3g (sat 3g); Sodium 488mg