Cook the Book: Poached Salmon with Beurre Blanc

Name: Cook the Book: Poached Salmon with Beurre Blanc
Ingredients: For the court-bouillon:; 2 pints water; 2 carrots, peeled and sliced; 1 large onion, peeled and sliced; 1 celery stick, sliced; 2 cloves; A few peppercorns; 2 bay leaves; 1 tablespoon salt; 2 tablespoons white wine vinegar; 2-pound piece of wild salmon, on the bone; For the beurre blanc:; 6 tablespoons white wine vinegar; 1/4 cup water; 4 shallots, peeled and very finely chopped; Salt and white pepper; 1 cup cold, unsalted butter, cut into cubes; A squeeze of lemon juice