Bring a large pot of water to a rolling boil. Add 1 tsp salt (optional) and the noodles. Cook according to package instructions until just al dente (usually 3–5 minutes for fresh noodles, 5–8 for dried). Stir occasionally so noodles don’t stick.

Shock and chill

Prepare a large bowl with 4 cups cold water and 1 cup ice. As soon as the noodles are al dente, drain them in a colander and immediately transfer to the ice water to stop cooking and firm the texture. Swirl for 30–60 seconds until fully chilled. Drain very well and gently toss with 1 tsp neutral oil (optional) to prevent sticking; set aside in the colander to drain further.

Spicy Paste Sauce

Combine base pastes

In a medium mixing bowl add 3 tbs gochujang, 2 tbs sesame paste (or tahini), 2 tsp chili crisp (start with 1 tsp if you prefer milder), and 2 tbs soy sauce. Whisk to begin combining into a thick paste.

Season and loosen

Add 1 tbs black or rice vinegar, 1 tbs fresh lime or lemon juice, 1 tsp sugar or honey, 2 tsp minced garlic, and 1 tsp grated ginger. Whisk again. Gradually add 3 tbs warm water, a tablespoon at a time, until the sauce reaches a pourable but still creamy consistency. Stir in 1 tsp toasted sesame oil, 1/2 tsp salt, and 1/4 tsp freshly ground black pepper. Taste and adjust: more vinegar for tang, more chili crisp for heat, more water to loosen.

Optional: emulsify

If you prefer an ultra-smooth sauce, transfer to a small blender or use an immersion blender for a few seconds to emulsify. Scrape down sides and make final seasoning adjustments.

Tossing & Assembly

Combine noodles and sauce

Transfer well-drained cold noodles to a large mixing bowl. Pour about two-thirds of the spicy paste over the noodles and toss thoroughly with tongs or chopsticks until evenly coated. Add more sauce to taste, reserving a small bowlful for serving if desired.

Add toppings and protein

Arrange julienned cucumber and carrot over the coated noodles. Add shredded roasted chicken or sliced cold tofu if using. Halve soft-boiled or soy-marinated eggs and place on top. Sprinkle with thinly sliced scallion whites and green tops, toasted sesame seeds, crushed peanuts, crispy fried shallots or garlic, and cilantro leaves as desired.

Final seasoning

Drizzle remaining sauce or an extra 1 tsp chili oil over the plated noodles for additional heat. Taste one forkful and adjust with a pinch of salt, more lime juice, or more chili crisp as needed.

Serve

Serve immediately while the noodles are cold and bright. Provide extra chili crisp and lime wedges on the side for individual adjustment.