Ingredients

• ½ cup plain whole-milk strained yogurt, such as greek-style
• ½ cup chopped fresh parsley leaves
• 2 tablespoons chopped fresh tarragon leaves
• 2 tablespoons chopped fresh chives
• 1 tablespoon capers, rinsed and chopped
• 1 clove garlic, grated
• 1 ½ teaspoons grated lemon zest
• ¼ cup lemon juice
• 1 medium avocado, cut into 8 slices
• ¼ teaspoon salt
• 4 slices hearty whole-wheat bread (1/2-inch)
• 1 cup watercress or spinach, divided
• 1 cup thinly sliced cucumber, divided
• ½ cup alfalfa sprouts, divided