In the Instant Pot insert, add the chicken stock, coconut milk, red curry paste, garlic, ginger, and chicken breast. Cook on high pressure for 5 minutes.
While the Instant Pot is doing it’s thing, slice the shallots, cut the lime, and wash the cilantro. If you’re using any extra toppings, prep them now. Cook and drain your noodles and divide them between two deep bowls.
When the Instant Pot is done, quick release the pressure. Carefully remove the chicken and shred. Add the chicken to the bowls with the noodles.
Stir the fish sauce and brown sugar into the soup. Taste the soup and adjust the seasoning with fish sauce, sugar, and curry paste if needed, then divide evenly between the two bowls. Finish with lime and cilantro and enjoy!