Shrimp and Leek Risotto

Name: Shrimp and Leek Risotto
Ingredients: 4 ½ cups hot Chicken Stock, Vegetable Stock, or canned reduced-sodium chicken broth; 1 pound medium shrimp; 5 tablespoons extra virgin olive oil; 1 medium onion, minced (about ¾ cup); 1 medium leek, white parts only, trimmed, cleaned, and chopped (about 1 cup); 4 to 6 scallions, trimmed, white and green parts chopped separately; 2 cups Arborio or Carnaroli rice; 1/3 cup dry white wine; Salt; 2 tablespoons unsalted butter, cut into 4 pieces; 1/3 cup freshly grated Parmigiano-Reggiano cheese; Freshly ground black pepper