Poached Salmon with Leek Sauce

Ingredients

• 2-pound salmon fillet
• 4 fresh dill sprigs
• 1 large onion, sliced
• 6 black peppercorns
• 2 cups white wine
• 3 tablespoons extra virgin olive oil
• 1 small garlic clove, minced
• 2 large leeks, trimmed, cleaned, and cut into coins or half moons
• 1 teaspoon fine sea salt, more to taste
• 1/2 teaspoon freshly ground black pepper, more to taste
• 1 tablespoon unsalted butter