Poach scallops in salted water with bouquet garni until it is almost cooked and then remove them to a plate lined with paper towel to drain. Reduce the scallop liquid to 1 cup. In another skillet melt butter and onions and cook until softened. Add mushrooms, salt and pepper and cook until mushrooms are softened for about 5 minutes. Then add wine and reduce by half. Add reserve shallot broth and 1 cup cream and reduce until lightly thickened. Season with lemon juice. Return scallops to pan and simmer just until heated through. Garnish with fresh dill.