Rinse and dry romaine lettuce thoroughly, then chop or tear into bite-sized pieces to measure 6 cups. Place in a large shallow serving bowl or on a platter. Halve 1.5 cups of cherry tomatoes and scatter evenly over the greens.

Add proteins and cheese

Dice 2 cups of cooked chicken breast and spread in a row or scattered over the salad. Chop 3 hard-boiled eggs and distribute across the salad. Crumble 6 cooked bacon slices and sprinkle over. Add 1 cup shredded sharp cheddar evenly. If using, dice 1 avocado and tuck pieces into the salad to avoid browning. Sprinkle 2 tablespoons thinly sliced green onions for mild onion flavor.

Ranch Dressing

Make the ranch dressing: In a medium bowl whisk together 1/2 cup mayonnaise, 1/2 cup buttermilk and 1/4 cup sour cream until smooth and slightly thin. Stir in 2 tablespoons chopped fresh chives, 1 tablespoon chopped fresh parsley, 1/2 teaspoon garlic powder, 1/2 teaspoon onion powder, 1/2 teaspoon dried dill, 1/2 teaspoon salt, 1/4 teaspoon black pepper and 1 teaspoon lemon juice or white vinegar. Taste and adjust seasoning or thickness—add more buttermilk for a thinner pourable dressing or a little extra sour cream for thicker dip-style ranch. Chill for at least 10 minutes to let flavors meld (can make up to 24 hours ahead).

Optional: for a smoother dressing, blend ingredients in a small blender or with an immersion blender for 10–15 seconds.

Assembly & Finish

Arrange final toppings: Just before serving, give the lettuce a gentle toss if you prefer mixed salad, or leave composed in rows (classic Cobb style). Drizzle the prepared ranch dressing over the salad to taste (about 1/2–3/4 cup for lightly dressed; serve extra on the side).

Garnish and serve: Sprinkle the extra 1/4 cup shredded cheddar, a light dusting of cracked black pepper (about 1/4 tsp) and 1/4 tsp kosher salt across the top. Serve immediately so avocado remains fresh and bacon stays crispy.