Broccoli and Cheddar Gratin

Name: Broccoli and Cheddar Gratin
Ingredients: 2 slices white sandwich bread , each slice torn into quarters (about 2 1/2 ounces); 2 tablespoons unsalted butter , softened; 1/4 teaspoon table salt; 1/8 teaspoon ground black pepper; 1 tablespoon table salt plus an additional 1/4 teaspoon; 2 pounds broccoli (about 1 large bunch), florets trimmed to 1-inch pieces, stalks peeled and chopped medium; 2 tablespoons unsalted butter; 1 medium shallot , minced (about 2 tablespoons); 1 clove garlic , minced; 1 tablespoon unbleached all-purpose flour; 3/4 cup heavy cream; 3/4 cup low-sodium chicken broth; pinch fresh ground nutmeg; pinch cayenne pepper; 1 teaspoon minced fresh thyme leaves; 4 ounces grated sharp cheddar cheese (about 1 cup)