Step 1

Whisk oil, lemon juice, dill, tarragon, cilantro, green onion, and mustard in small bowl. Season with salt and pepper. DO AHEAD Can be made 1 day ahead. Cover and chill.

Step 2

Line baking sheet with waxed paper. Whisk first 10 ingredients in large bowl. Mix in crabmeat and 1 cup panko, breaking up crabmeat slightly. Let stand 10 minutes. Place remaining panko on rimmed baking sheet, spreading slightly. Form crab mixture into sixteen 2-inch-diameter patties, using about scant 1/4 cup for each. Press both sides of patties into panko. Transfer patties to waxed-paper-lined baking sheet. Cover and chill at least 1 hour and up to 1 day.

Step 3

Melt 1 tablespoon butter with 1 tablespoon oil in each of 2 heavy large skillets over medium-high heat. Add crab cakes to skillets and cook until golden on both sides, adding more butter and oil as needed, about 5 minutes total.

Step 4

Place salad mix in very large bowl. Add 1/2 cup vinaigrette; toss. Arrange crab cakes on platter. Garnish with herb sprigs, drizzle with some of remaining vinaigrette, and serve with salad.