In a large sauté pan over medium heat, melt 2 tablespoons of butter. Add the garlic and green onion and cook for 3-5 minutes or until softened, stirring occasionally. Add the cockles and cook for another 5 minutes. Add the white wine and bouillon cubes with water or the chicken broth. Bring to a boil then reduce to a rolling simmer and cook until the clams open up, stirring occasionally. Remove from the heat and stir in the lemon juice. Add the remaining tablespoon of butter and the cream and stir. Garnish with parsley and serve immediately. Serve with sourdough bread.