Lobster and Shrimp Mac and Cheese

Name: Lobster and Shrimp Mac and Cheese
Ingredients: 12 ounces fusilli or rotini pasta; 4 frozen lobster tails*, thawed (about 1 ½ lbs frozen); Olive oil; Salt and pepper; 2 cups chicken or vegetable stock; ½ lb large raw shrimp, about 12, peeled, deveined, tails removed; 2 cups whole milk; 2 tablespoons butter; 2 tablespoons all-purpose flour; 8 ounces fontina cheese, freshly grated; 4 ounces creamy jack, gouda or gruyere cheese, freshly grated; ¼ teaspoon freshly grated nutmeg; Salt and pepper, to taste; Chives for garnish