Turkey Spaghetti

Name: Turkey Spaghetti
Ingredients: Kosher salt and freshly ground black pepper; 3 tablespoons unsalted butter, plus more for buttering the pan; 8 ounces spaghetti; 1 teaspoon ground cumin; 4 scallions, sliced (green and white parts kept separate); 3 cloves garlic, chopped; 2 tablespoons all-purpose flour; 2 cups whole milk; 2 cups shredded Mexican blend cheese; 2 cups shredded Monterey Jack cheese; 4 cups shredded cooked turkey; 1 to 2 tablespoons sliced pickled jalapenos, chopped, plus 1 tablespoon brine; 1 medium tomato, chopped