In a pan, put the oil and then saute the garlic and shrimp lightly for about a minute. Now add the squid and mussels. Wait for the mussels to open. Do all this on low heat to avoid overcooking the shrimp which will deteriorate in its taste and nutrition value. Now, add salt and pepper according to taste.
Use a spoon to take out the sea food and place in a bowl. Keep heating the remaining solution until it becomes thick in a paste form. Now add one bunch watercress followed by soy sauce. Add the shrimp back to this solution, stir well.
In a mixing bowl, combine the second bunch of watercress with sliced red onion, tomatoes, bean sprouts, chervil, chives, champagne vinegar and salt and pepper to taste.
Arrange the watercress mixture on the platter and top them up with the sea food you prepared. Put some on the sides too. Garnish by sprinkling some feta cheese.