Preparation In medium saucepan, combine shrimp shells and enough water to cover. (Refrigerate shrimp until used later in recipe.) Cover, place over high heat, and bring to boil. Reduce heat to moderately low and simmer 25 minutes, skimming foam occasionally. Pour stock through fine-mesh sieve into large bowl and set aside. In heavy, 6-quart pot over moderate heat, heat 3 tablespoons oil until hot but not smoking. Add bell pepper, half of onion, half of celery, half of carrots, half garlic, jalapeños, orange zest, 3 sprigs thyme, 2 bay leaves, 1 1/2 sprigs parsley, 1 tablespoon salt, and 1 teaspoon pepper. Sauté until tender, about 10 minutes. Add tomatoes and 1 1/4 cups wine, and simmer 3 minutes. Add shrimp stock and just enough water to cover vegetables, and simmer 20 minutes. Remove parsley, thyme, and bay leaves. Working in batches, purée in blender until smooth. Keep warm. In medium saucepan over moderately low heat, bring chicken stock to simmer. Cover; keep warm over low heat. In heavy, large saucepan over moderately high heat, heat 3 tablespoons oil until hot but not smoking. Add remaining onions, celery, carrots, and garlic; remaining 3 sprigs thyme, 2 bay leaves, and 1 1/2 sprigs parsley; and 1 tablespoon salt and 1 teaspoon pepper. Reduce heat to moderate and sauté until vegetables are tender, about 10 minutes. Add rice and cook, stirring constantly, until rice is fully coated with oil, about 1 to 2 minutes. Add remaining 1 1/4 cups wine and cook, stirring occasionally, until wine is almost completely absorbed, about 4 to 5 minutes. Add 3/4 cup chicken stock and simmer, stirring occasionally, until liquid is absorbed. Continue adding stock, 3/4 cup at a time, stirring and letting each addition be absorbed before adding the next, until rice is creamy-looking but still al dente, about 30 to 40 minutes. (There may be leftover stock.) Remove herbs, then stir in butter, lemon zest and juice, 2 teaspoons salt, and 1/2 teaspoon pepper. Cover risotto and keep warm. Sprinkle shrimp with remaining 2 teaspoons salt and 1/2 teaspoon pepper. In large sauté pan over moderate heat, heat remaining 2 tablespoons oil until hot but not smoking. Add shrimp and sauté until pink, about 2 to 3 minutes. Remove from heat and keep warm. Divide risotto evenly among 10 bowls, mounding in center of each bowl. Top each mound with 6 shrimp. Spoon sauce around risotto and garnish with scallions and thyme leaves.
Preparation In medium saucepan, combine shrimp shells and enough water to cover. (Refrigerate shrimp until used later in recipe.) Cover, place over high heat, and bring to boil. Reduce heat to moderately low and simmer 25 minutes, skimming foam occasionally. Pour stock through fine-mesh sieve into large bowl and set aside. In heavy, 6-quart pot over moderate heat, heat 3 tablespoons oil until hot but not smoking. Add bell pepper, half of onion, half of celery, half of carrots, half garlic, jalapeños, orange zest, 3 sprigs thyme, 2 bay leaves, 1 1/2 sprigs parsley, 1 tablespoon salt, and 1 teaspoon pepper. Sauté until tender, about 10 minutes. Add tomatoes and 1 1/4 cups wine, and simmer 3 minutes. Add shrimp stock and just enough water to cover vegetables, and simmer 20 minutes. Remove parsley, thyme, and bay leaves. Working in batches, purée in blender until smooth. Keep warm. In medium saucepan over moderately low heat, bring chicken stock to simmer. Cover; keep warm over low heat. In heavy, large saucepan over moderately high heat, heat 3 tablespoons oil until hot but not smoking. Add remaining onions, celery, carrots, and garlic; remaining 3 sprigs thyme, 2 bay leaves, and 1 1/2 sprigs parsley; and 1 tablespoon salt and 1 teaspoon pepper. Reduce heat to moderate and sauté until vegetables are tender, about 10 minutes. Add rice and cook, stirring constantly, until rice is fully coated with oil, about 1 to 2 minutes. Add remaining 1 1/4 cups wine and cook, stirring occasionally, until wine is almost completely absorbed, about 4 to 5 minutes. Add 3/4 cup chicken stock and simmer, stirring occasionally, until liquid is absorbed. Continue adding stock, 3/4 cup at a time, stirring and letting each addition be absorbed before adding the next, until rice is creamy-looking but still al dente, about 30 to 40 minutes. (There may be leftover stock.) Remove herbs, then stir in butter, lemon zest and juice, 2 teaspoons salt, and 1/2 teaspoon pepper. Cover risotto and keep warm. Sprinkle shrimp with remaining 2 teaspoons salt and 1/2 teaspoon pepper. In large sauté pan over moderate heat, heat remaining 2 tablespoons oil until hot but not smoking. Add shrimp and sauté until pink, about 2 to 3 minutes. Remove from heat and keep warm. Divide risotto evenly among 10 bowls, mounding in center of each bowl. Top each mound with 6 shrimp. Spoon sauce around risotto and garnish with scallions and thyme leaves.