PreparationFor the Sour Cream Dressing: Whisk sour cream, mayonnaise, garlic, lemon zest, lemon juice, salt, and pepper in a medium bowl to combine. Do Ahead: Dressing can be made 1 day ahead. Cover and chill. For the salad: Trim root end of lettuce; discard any wilted outer leaves. Cut into quarters lengthwise, then cut each quarter crosswise into 3" pieces. Without separating wedges into leaves, transfer to a large platter. Tuck avocado pieces among lettuce and drizzle lemon juice over; season with salt. Spoon half of dressing over salad and top with chives; season with pepper. Serve with remaining dressing alongside.
PreparationFor the Sour Cream Dressing: Whisk sour cream, mayonnaise, garlic, lemon zest, lemon juice, salt, and pepper in a medium bowl to combine. Do Ahead: Dressing can be made 1 day ahead. Cover and chill. For the salad: Trim root end of lettuce; discard any wilted outer leaves. Cut into quarters lengthwise, then cut each quarter crosswise into 3" pieces. Without separating wedges into leaves, transfer to a large platter. Tuck avocado pieces among lettuce and drizzle lemon juice over; season with salt. Spoon half of dressing over salad and top with chives; season with pepper. Serve with remaining dressing alongside.