Wash and dry romaine lettuce and baby spinach thoroughly. Chop or tear the romaine into bite-size pieces and place both greens in a large salad bowl or on a serving platter; chill if desired.

Prepare proteins and vegetables

If not already cooked, cook chicken breast (see note) and dice into 1/2-inch pieces. Quarter the hard-boiled eggs. Cook bacon until crisp, drain on paper towels and crumble. Halve cherry tomatoes, peel/seed and dice cucumber, thinly slice red onion, and slice the avocado just before assembling to prevent browning.

Arrange Cobb

On top of the bed of greens, arrange the diced chicken, quartered eggs, crumbled bacon, halved tomatoes, diced cucumber, sliced avocado, crumbled blue cheese, and sliced red onion in rows or clusters so each ingredient is visible. Sprinkle extra chives and cracked black pepper over the salad if using.

Avocado Ranch Dressing

Blend dressing

In a blender or food processor add the ripe avocado (peeled and pitted), mayonnaise, buttermilk, sour cream, cilantro (or parsley), chopped chives, minced garlic, lemon juice, white wine vinegar, dried dill, kosher salt, and black pepper. Blend on medium until smooth and creamy. If dressing is too thick, add water 1 tablespoon at a time until desired consistency is reached (about 2 tablespoons). Taste and adjust salt, pepper or lemon juice as needed.

Chill and finish

Transfer the dressing to a jar or bowl and refrigerate for at least 15 minutes to let flavors meld. Stir or shake before serving.

To serve

Just before serving, drizzle the avocado ranch dressing over the arranged Cobb salad or serve on the side. Toss gently if you prefer a mixed salad, or allow diners to take portions with all components intact. Garnish with extra chopped chives and additional cracked black pepper to taste.