Ingredients

• 12 ounces campanelle (trumpet-shaped pasta) or macaroni
• 1/8 teaspoon crushed saffron threads
• 7 tablespoons fresh lemon juice, divided
• 6 tablespoons extra-virgin olive oil, divided
• 1/2 cup mayonnaise
• 1/2 cup sour cream
• 1/4 cup thinly sliced green onions
• 2 tablespoons drained capers
• 2 tablespoons minced fresh tarragon plus sprigs for garnish
• 1 tablespoon minced fresh dill plus sprigs for garnish
• 1 teaspoon sugar
• 1 pound cooked medium shrimp
• 1 cup finely chopped celery
• 1/2 pound Dungeness crabmeat
• 2 large handfuls of arugula
• 2 small heads of butter lettuce
• Lemon wedges

Instructions

1. Cook pasta in large pot of boiling salted water until tender but still firm to bite, stirring occasionally. Drain, reserving 1/2 cup cooking liquid. Place 3 tablespoons hot cooking liquid in medium bowl. Sprinkle saffron over and let stand at room temperature 5 minutes. Transfer pasta to large bowl. Drizzle pasta with 1 tablespoon lemon juice and 1 tablespoon oil; toss to coat. Let stand at room temperature until cool, stirring occasionally.
2. Add mayonnaise, sour cream, green onions, capers, minced tarragon, minced dill, sugar, remaining 6 tablespoons lemon juice, and remaining 5 tablespoons oil to bowl with saffron liquid. Whisk to combine. Season saffron dressing to taste with salt and pepper. Pour dressing over pasta. Add shrimp and celery; toss to coat. Add reserved pasta cooking liquid by tablespoonfuls if mixture is dry. Add crab; toss gently. Cover and refrigerate at least 1 hour and up to 4 hours.
3. Line platter with arugula and butter lettuce leaves. Spoon pasta over greens. Garnish with lemon wedges and tarragon and dill sprigs. Serve cold.