How to Make It
Prepare the Curry Paste: Place chiles in a heat proof bowl and add enough boiling water to cover (about 3 cups). Cover with plastic wrap; set aside, allowing chiles to soak until soft, 20 to 30 minutes.
Drain chiles; reserve liquid. Process chiles, garlic, shallots, ginger, cilantro, lemongrass, turmeric, coriander, cardamom, curry, and 1/4 cup of the soaking liquid in a food processor until smooth, adding more liquid by the tablespoon if needed. (Curry Paste can be made ahead, and refrigerated up to 2 weeks.)
Prepare the Soup: Set Instant Pot to high Sauté for 10 minutes. Add oil; heat 1 min. Add Curry Paste to hot oil; cook, stirring constantly, until paste has darkened slightly, 5 to 6 minutes. Stir in coconut milk, chicken broth, and salt; bring to a boil. Add chicken.
Place lid on the Instant Pot, and set vent to seal. Set to High Pressure for 10 minutes. When time is done, release pressure. Once pressure has released naturally, carefully remove lid, and transfer chicken to a plate to cool. When chicken is cool enough to handle, shred the meat.
Prepare noodles according to package directions.
Stir fish sauce, brown sugar, and shredded chicken into soup. Divide noodles and soup among serving bowls; serve with desired toppings.