Pat the chicken breasts dry with paper towels. Rub both sides with 1 tablespoon olive oil, then evenly season with 1 teaspoon kosher salt and 1/2 teaspoon freshly ground black pepper.

Grill chicken

Preheat an outdoor grill or grill pan to medium-high (about 400°F / 200°C). Place the chicken on the hot grill and cook 5-6 minutes per side, or until an internal temperature of 165°F (74°C) is reached. Remove from heat and tent loosely with foil; rest 5 minutes to retain juices.

Prep lettuce and vegetables

While the chicken rests, chop the romaine into bite-sized pieces and place in a large bowl. Halve the cherry tomatoes. Thinly slice the red onion into rings and separate. Slice the avocado just before plating to prevent browning.

Assemble salad

Slice the rested chicken thinly against the grain. Add the tomatoes, red onion, and avocado slices to the romaine. Toss gently to combine. Arrange the chicken slices on top and sprinkle 1/2 cup crumbled blue cheese over the salad.

Finish

Serve the salad immediately with a side bowl or ramekin (about 1/4 to 1/3 cup) of green goddess dressing for drizzling or dipping.

Green Goddess Dressing (side)

In a medium bowl or a blender/food processor, combine 1/2 cup mayonnaise, 1/4 cup plain Greek yogurt, 1/4 cup packed fresh parsley, 2 tablespoons chopped chives, 1 tablespoon fresh tarragon (or 1 tablespoon dried), 1 tablespoon lemon juice, 1 teaspoon white wine vinegar, 1/2 teaspoon anchovy paste (if using), and 1 minced garlic clove.

Blend or whisk while slowly streaming in 2 tablespoons olive oil until the dressing is smooth and emulsified. If the dressing is too thick, add up to 1 teaspoon cold water, a few drops at a time, until you reach the desired consistency.

Season the dressing to taste with 1/2 teaspoon salt and 1/4 teaspoon freshly ground black pepper. Adjust lemon juice or vinegar if you prefer brighter acidity.

Transfer dressing to a small serving bowl or ramekin and chill briefly if time allows (10–15 minutes) to let flavors meld. Store any leftover dressing covered in the refrigerator for up to 3 days.