1. Discard any gaping mussels that do not close when the shells are tapped.
2. In a 6- to 8-quart pan over high heat, stir oil and chilies until chilies are limp, 1 to 2 minutes.
3. Add chicken broth, canned coconut milk, ground turmeric, and rice vinegar. Bring mixture to a boil.
4. Add mussels, cover, and cook until shells open, 6 to 10 minutes.
5. Ladle the mussels and broth into wide bowls.
6. Spoon pineapple chunks equally over mussels and sprinkle portions with cilantro. Season to taste with salt.
7. Serve mussels with bread to dip into the broth as you eat.