Prep time: 15 minutes. Cook time: 0 minutes when using fully cooked, ready-to-eat crab. Chill time: 20 to 30 minutes. Total time: 35 to 45 minutes. Servings: 4 to 6; nutrition estimates assume 6 servings. Use 1 pound imitation crab meat or fully cooked real lump crab meat, 1 cup finely diced celery, 1/4 cup diced green onions, 2 tablespoons finely chopped fresh dill or parsley, and optional 2 tablespoons finely diced red onion. For the dressing, whisk 3/4 cup mayonnaise, 2 tablespoons sour cream or plain Greek yogurt, 2 tablespoons fresh lemon juice, 1 teaspoon Dijon mustard, 1 teaspoon Old Bay seasoning, 1/2 teaspoon garlic powder, 1/4 teaspoon black pepper, and approximately 1/8 teaspoon salt or to taste. Combine crab and vegetables in a large bowl, add dressing, and fold gently until evenly coated. Cover and refrigerate for approximately 20 to 30 minutes before serving. Serve chilled in lettuce cups, on crackers, as a sandwich filling, or on its own. Use fully cooked crab meat only for this no-cook recipe. If using real lump crab, check gently for shell fragments and preserve the larger pieces while mixing. Imitation crab usually contains fish and may contain wheat or shellfish ingredients; review labels for allergens. Old Bay seasoning and imitation crab can contribute salt, so taste before adding extra. Refrigerate promptly in an airtight container at 40°F (4°C) or colder and enjoy within 2 days for best quality. For outdoor gatherings, keep the serving bowl over ice and do not leave the seafood salad at room temperature for more than 2 hours, or 1 hour above 90°F (32°C). Avoid freezing because mayonnaise dressing can separate. Nutrition estimates are approximate per serving and assume imitation crab, regular mayonnaise, sour cream, optional red onion, and 6 servings. Exact values depend on the seafood type, mayonnaise brand, yogurt or sour cream, and portion size.