Step 1

Scrub and debeard the mussels if they haven't already been debearded. Discard any that aren't tightly closed or that don't close when you tap them.

Step 2

Slice the onions thinly on a 45° angle. Remove the tough outer leaves of the lemongrass stalk and cut it into short lengths, about 1 inch long.

Step 3

Mince the garlic, remove the leaves from the cilantro stalks and chop the stems.

Step 4

Slice the chili pepper very thinly.

Step 5

Heat the oil in a heavy bottomed pan. Add the onions, lemongrass, garlic, and cilantro stems and cook, stirring until softened but not browned.

Step 6

Add the coconut milk, Thai red chili pepper and fish sauce to the pot. Bring to a boil.

Step 7

Add the mussels all at once. Cover the pot and steam the mussels for 4-5 minutes until opened. Discard any that do not open.

Step 8

Ladle into bowls and garnish with a squeeze of lime juice and some fresh cilantro leaves. Serve immediately.