1/4 cup chopped flat-leaf parsley 3 Tbsp chopped cilantro, plus whole sprigs for garnish 1-1/2 Tbsp fresh lemon juice 1/2 Tbsp sweet paprika 1 Tbsp fresh ginger, finely minced or microplaned Small pinch of saffron threads, crumbled 1/4 cup extra-virgin olive oil 1 pound large shrimp, shelled and deveined 1-3/4 pounds plum tomatoes, peeled, seeded and coarsely chopped 3 garlic cloves, minced 2 tsp ground cumin 1/4 to 1/2 tsp red pepper flakes Salt and freshly ground pepper 2 large carrots, thinly sliced 1 medium sweet onion, thinly sliced 1 pound waxy potatoes (like Red Bliss or Yukon Gold), thinly sliced 1 medium red bell pepper, cut into thin strips 1 medium yellow or orange bell pepper, cut into thin strips 1/2 preserved lemon, peel only, thinly sliced 1/3 cup pitted bright green olives, like Sicilian or Castelvetrano Mix parsley, chopped cilantro, lemon juice, paprika, ginger, saffron and olive oil in a medium bowl. Add shrimp, toss to coat and marinate for 2 hours in the refrigerator. In the meantime, mix the tomatoes with the garlic, cumin, red pepper flakes and season with salt and pepper in a medium saucepan. Simmer, stirring occasionally, until the tomatoes have broken down and are slightly thickened, approximately 10 minutes. In a large tagine, enameled cast-iron casserole or Dutch oven, spread the carrots on the bottom, season with salt and pepper. Then, add the onions, potatoes and bell peppers in individual layers, seasoning each layer with salt and pepper. Evenly spread the tomato sauce on top. Cover and simmer until the vegetables are just beginning to get tender, about 15-20 minutes. Then, add the preserved lemon and olives to the casserole and arrange the shrimp on top in a single layer. Evenly distribute any remaining marinade over top. Season with salt and pepper. Cover and cook over moderately low heat until the shrimp are pink and beginning to curl, about 2-3 minutes. Remove the shrimp to a plate. Increase the heat to medium and cook uncovered, stirring once or twice, until nearly all the juices have evaporated, about 5 minutes. Be careful not to let it burn on the bottom. Transfer the vegetables to a serving bowl and top with the shrimp. Garnish with cilantro sprigs and serve.