Wash mussels and de-beard, bring a pot of water to a boil and cook the mussels, once shells open, take out mussels, discard shells and put the mussels into a mixing bowl, set aside. Keep the water in the pot and continue to bring to boil.
Wash squids and cut into bite size, blanch in the same pot of water used to cook mussels, drain and mix with mussels.
Wash mint leaves, corianders and use the leaves whole. Wash tomatoes and slice into thin wedges.
Onion and shallots skin off and sliced. Wash bird eyes chilies (if you want milder flavor, replace with big chilies) cut into small pieces.
Toss in sliced onion, shallots, chilies and tomatoes.Add in seasoning, mix well, taste test. Add more fish sauce or lime juice if desire stronger flavour.
Top with mint and coriander leaves and gently toss together.Serve on a platter lined with lettuce and garnish with extra mint leaves.