In the same skillet, heat the remaining 3 tablespoons of olive oil over moderate heat. Add the tomatoes and cook for 3 minutes. Stir in the garlic, 1 tablespoon of the parsley, the serrano chile and the paprika. Add the chicken stock, clam juice and saffron, season with salt and bring to a boil. Add the capellini and cook, stirring occasionally, until the pasta is al dente and has absorbed most of the sauce, about 5 minutes. Return the shrimp and monkfish to the skillet along with any accumulated juices and toss well. Transfer the pasta to bowls and garnish with the remaining 1 tablespoon of parsley. Serve with lemon wedges.