Put a kettle of water on to boil for cooking linguine.
In a bowl toss shrimp with 1 teaspoon oil, 1/8 teaspoon red pepper flakes, and salt and pepper to taste. Heat a 12-inch non-stick skillet over moderately high heat until hot enough to make drops of water scatter and saute shrimp in 2 batches until golden and cooked through, 1 to 2 minutes on each side, transferring as cooked to a plate.
To skillet add wine and boil until most is evaporated. Add remaining 1/2 teaspoon oil, onion, garlic, remaining 1/8 teaspoon red pepper flakes, and salt and pepper to taste and cook over moderate heat, stirring, until onion is softened. In a bowl whisk together tomato paste and chicken broth and add to skillet with fennel and bell pepper. Simmer mixture, covered, until fennel is tender, about 10 minutes.
In a very small bowl or ramekin combine hot water and saffron.
While fennel mixture is simmering, add salt to taste and linguine to boiling water and cook until al dente. Drain linguine well in a colander and return to kettle. Toss linguine with saffron mixture until evenly coated and keep warm.
To simmering fennel mixture add tomatoes and fish stock and simmer 2 minutes. Add shrimp and spinach and cook, covered, until just heated through until spinach is slightly wilted, 1 to 2 minutes. To pasta add vegetable mixture, parsley, and salt and pepper to taste and toss well.
Per serving: 1613 Calories (kcal); 24g Total Fat; (13% calories from fat); 114g Protein; 225g Carbohydrate; 534mg Cholesterol; 1640mg Sodium Food Exchanges: 12 1/2 Grain(Starch); 10 Lean Meat; 6 1/2 Vegetable; 0 Fruit; 1 1/2 Fat; 0 Other Carbohydrates