Gather all ingredients and equipment.
Place the cilantro stems, 1/2 of the garlic, 1/2 of the shallot, coriander seeds, red pepper flakes, lime zest, and the salt in a spice grinder or mortar and pestle. Grind until a smooth aromatic paste is formed. Set aside.
Heat a medium saute pan over medium heat. Add the oil and heat until simmering. Add remaining garlic, shallot, aromatic paste, ginger, and green curry paste to pan.
Cook for about 4 minutes, or until very aromatic, while stirring frequently, taking care to scrape the bottom of the pan to avoid burning.
Add the coconut milk, sugar, and fish sauce.
Bring to a simmer and cook for about 3 minutes.
Add scrubbed and debearded mussels to the pan. Stir and cover tightly.
Shake the pan vigorously every 30 seconds or so to stir while cooking. Cook mussels for 3 – 4 minutes or until mussels open.
Discard any unopened mussels.
Pour into serving bowl. Top with lime juice. Garnish with cilantro leaves, sliced pepper, and lime wedges.
Serve.
