Add oil to a large soup pot over medium heat. Thinly slice shallots and add to pot along with ginger and garlic. Sauté until golden, 3–5 minutes. Meanwhile, bring a large pot of water to boil for the noodles.
Once the shallots are golden, add in curry paste and powder. Stir constantly for 2–4 minutes or until very fragrant—don’t rush this; we’re creating the foundation of flavor. Increase heat to medium high, and while stirring constantly and scraping the bottom of the pot, gradually add in 1 cup of chicken stock until incorporated. Add in the rest of the chicken stock and the coconut milk. Stir until smooth.
Bring to a simmer. Once simmering, reduce heat to maintain a gentle simmer and cook (uncovered) for 5 minutes. Add in frozen peas, soy sauce, and 2 tablespoons lime juice. Taste and season with salt and pepper. (I typically add 1/4 teaspoon of each.) Here’s where you can take a minute to adjust other flavors—see note 5.
Meanwhile, the water should be boiling. Discard seasoning packets and boil the noodles according to package directions. Drain but do not rinse. Right after draining, use tongs to divide the noodles equally among 4 soup bowls. Dice the chicken and divide evenly among the bowls (1/2 cup per bowl).
When ready to serve, ladle broth and peas right on top of the noodles and chicken. Garnish bowls, if desired, with fresh cilantro, thinly sliced green onions, additional lime wedges, and a drizzle of Sriracha if desired. Enjoy immediately.
Notes
Note 1: To keep things quick, use refrigerated minced garlic and refrigerated ginger paste.Note 2: Red curry paste provides the main flavor for this soup. You’ll likely find it in the international section of your grocery store, at an Asian grocery store, or online. I’ve tested both Maesri® and Thai Kitchen® in this recipe. The intensity and flavor will vary from brand to brand. Add to preference, and if you aren’t sure, start with less since you can always add more later.Note 3: The coconut milk really offsets the spice of the curry paste, so be sure to get a full-fat one. (Lite coconut milk also won’t thicken as nicely.)Note 4: Serving suggestions: 2–3 teaspoons light brown sugar if needed, cilantro, extra lime wedges, green onions, and Sriracha.Note 5: After the soup has simmered, it’s time to bring the flavors alive! Add extra fresh lime juice, soy sauce, curry paste salt, etc. all to personal preference. You may even need to add a few teaspoons of sugar. The amounts will vary based on the curry paste and coconut milk used and your taste preferences. Salt is important in helping to bring out and enhance existing flavors.Storage: If you’d like to have this soup for leftovers, keep the noodles and chicken separate from the broth. Combine the two just before eating.