Ingredients

• 1 ½ tablespoons extra-virgin olive oil
• 4 (5 ounce) skinless salmon fillets (see tip)
• 1 teaspoon ground pepper, divided
• ⅛ teaspoon salt plus 1/2 teaspoon, divided
• ½ cup buttermilk
• ¼ cup nonfat plain greek yogurt
• ¼ cup grated parmigiano-reggiano cheese
• 2 tablespoons lemon juice
• 1 ½ teaspoons worcestershire sauce
• 1 teaspoon grated garlic
• ½ teaspoon dijon mustard
• 5 cups chopped romaine lettuce
• 3 cups chopped radicchio
• 3 tablespoons thinly sliced fresh basil, plus more for garnish
• 1 ½ tablespoons chopped fresh tarragon