Place clams and mussels in a large bowl of cold water. Add 1 - 2 tbsp of salt and 1/4 cup of flour. Allow to soak for one hour, then drain and rinse under cold water.
Heat a large pot of water over high heat. Once boiling, season with a good amount of salt - it should taste like the sea. If using dried pasta, add it to the water now.
In a large skillet or saucepan, heat the oil over medium-high heat. Add the shallots and green garlic and season with salt and pepper, to taste. Add the wine and simmer until the liquid has reduced by half, about 2 minutes. Stir in the chicken stock, clams and mussels. Season with salt and pepper, to taste. Bring the mixture to a simmer. Cover the pan with a tight-fitting lid and cook until all the shellfish have opened, about 5 to 8 minutes. Discard any unopened shellfish.
Once the clams and mussels have been cooking for a minute, add the fresh pasta to the water. Cook for about 3 minutes, or until al dente.
Using tongs, add the cooked pasta to the pot with the clams and mussels. Stir and cook for a minute till the pasta is done. Turn off the heat and add the butter and parsley. Give it all a good stir, and serve with a crusty baguette for dipping in the sauce.