Bibim Guksu (Spicy Cold Noodles)

Name: Bibim Guksu (Spicy Cold Noodles)
Prep time: 15 min
Cook time: 10 min
Total time: 25 min
Cuisine: Korean
Ingredients: 8 ounces buckwheat noodles (memil guksu) or wheat flour noodles (somyeon/somen); 1 small cucumber (about 3 ounces); 1 small carrot (about 3 ounces); 2 ounces red cabbage leaves; 2 ounces lettuce leaves; 1/2 cup thinly sliced kimchi; 1 boiled egg - optional; 1 tablespoon sesame oil (See note); 2 teaspoons sesame seeds; 3 tablespoons Korean chili pepper paste, gochujang; 1 tablespoon Korean chili pepper flakes, gochugaru; 1 teaspoon Korean/Asian hot mustard paste, gyeoja (optional); 2 tablespoons sugar (or corn syrup/oligo syrup) (adjust to taste); 2 tablespoons rice vinegar or apple cider vinegar (adjust to taste); 1 tablespoon soy sauce; 1 clove garlic minced; 2 tablespoons soft drink (such as ginger ale, Sprite, etc.), apple juice, orange juice, or 1 tablespoon of Korean plum syrup (maesilcheong)