Combine mayonnaise, sour cream, lemon juice, dried parsley, dried dill, dried chives, garlic powder, onion powder, salt, and black pepper in a medium bowl. Whisk thoroughly until the mixture is smooth and well blended. Add heavy cream one tablespoon at a time, whisking after each pour, until the dressing reaches your preferred thickness—thin enough to drizzle or thick enough to coat. Leave the dressing at room temperature while you prepare the other ingredients.

Lay the thick-cut bacon slices flat in a large skillet and place over medium-high heat. Cook for 8–10 minutes, stirring occasionally, until the bacon turns deeply browned and crispy throughout. Remove the bacon to a paper towel-lined plate to drain excess grease and cool. Once fully cooled, crumble the bacon into bite-sized pieces and set aside—it will crisp up further as it cools.

Use paper towels to pat the chicken breasts completely dry, then season both sides generously with salt, black pepper, paprika, and garlic powder. Heat the olive oil in a large skillet over medium-high heat until it shimmers. Carefully place the chicken breasts in the pan and sear for 5–6 minutes per side without moving them, which creates a golden crust and keeps the juices locked inside. The chicken is ready when an instant-read thermometer registers 165°F / 74°C at the thickest part. Transfer the chicken to a cutting board and let it rest for 5 minutes, then slice into bite-sized pieces.

While the chicken rests, prepare the remaining salad components: chop the romaine lettuce into bite-sized pieces, halve the cherry tomatoes, slice the hard-boiled eggs and avocados, and slice the green onions. Keep the avocado slices separate until just before serving to prevent browning—this ensures they stay vibrant and fresh-looking.

Arrange the chopped romaine lettuce in a large bowl or spread it across individual serving plates. Top the lettuce with the sliced chicken, crumbled bacon, sliced hard-boiled eggs, avocado slices, cherry tomatoes, green onions, and crumbled blue cheese, arranging them in neat rows or sections for a classic Cobb presentation. Drizzle the herb dressing over the top, or serve it on the side for guests to add themselves. Toss gently just before eating to mix all the flavors together.