Soak the instant ramen noodles in room temperature water until they expand, about 10-15 minutes depending on the brand.

Grill the northern Thai sausage (sai ua) over low heat, using 1-2 teaspoons of oil to help release its fat.

While the sausage is heating, dice the shallots into 1/2-inch cubes or as desired.

Cut the limes into wedges for serving.

Mix the coarsely ground dried chili flakes and ground black pepper together. For best flavor, use freshly ground black pepper for a coarse texture.

Keep an eye on the sausage. When the skin is crispy and fragrant, remove and set aside. If not yet done, continue grilling over low heat.

Cut the pork into 1-inch cubes.

Boil the egg for 7-8 minutes for a jammy yolk, or cook to your preferred doneness.

Once the sausage is ready, set it aside. Do not discard the leftover oil. Increase the heat until the oil smokes, then turn off the heat. Add the chili-pepper mixture and toast until fragrant. Transfer to a small bowl to serve as a condiment, along with the diced shallots and lime wedges.

Drain the soaked noodles, but save the soaking water if using brands like Wai Wai or Mama.

Prepare to cook the curry paste: Heat a pan over high heat until smoking, then add 2 tablespoons of oil and reduce to medium heat. Add the pork cubes and sear until browned on the outside but still pink inside. If experienced, you can use higher heat; otherwise, stick to medium. When you smell the aroma of the pork, proceed to the next step.

Add the khao soi curry paste and stir-fry over low heat to avoid burning. Mix well with the pork. Add 1/4 of the coconut milk and cook until slightly reduced, then add the remaining coconut milk.

Increase to medium heat. When the mixture boils, add all the reserved noodle soaking water. Bring to a strong simmer, then reduce to low and simmer for another 10-15 minutes. Taste and season with fish sauce and sugar as desired. Khao soi should be rich, salty, spicy, and slightly sweet. Adjust spiciness with the toasted chili condiment, not in the pot.

Add the prepared noodles to the khao soi broth and cook for 1 minute, then turn off the heat.

To serve, slice the reserved sausage and arrange on top with the peeled and halved boiled egg. Serve immediately.

Note: The author did not prepare pickled mustard greens, but if you have them, they make a great side. Mix 1 teaspoon of the toasted chili condiment with 1.75 oz (50 grams) of pickled mustard greens for serving.