Poached Salmon Steaks with Horseradish and Chive Sauce

Ingredients

• 2 cups 2% milk
• 1 1/2 cups water
• 2 tbsp lemon juice
• 1 small onion (thinly sliced)
• 1 stalk celery with leaves (coarsely chopped)
• 1 carrot (coarsely chopped)
• 4 black peppercorns
• 4 salmon steaks (about 115 g each)
• 1 tbsp bottled grated horseradish
• 1/2 cup low-fat sour cream
• 1/2 cup reduced-fat mayonnaise
• 2 tbsp fresh chives (chopped)
• freshly ground black pepper