Peel parsnip and potatoes. Cut into dices. Place in a sauce pan, cover with water and cook until tender. Bring down the head and add the soy cream or milk. Mix everything and season to taste. Add more water if the soup is too thick. Continue to cooking the soup on low heat while you focus on the scallops and mussels.
Remove the side muscle from the scallops. Clean the mussels and scallops. Sprinkle with salt.
Heat two skillets over high heat. In one skillet, add the mussels and cook until they are open, stirring occasionally. It takes about 5 minutes.
In the other skillet, grill the scallops in some olive oil, 2 minutes on each side.
Reheat the soup slightly if needed. Pour the soup in two bowls, add the mussels and scallops then top with chopped chives and croutons.