Broccoli and Beer Cheese Cocottes

Preheat oven to 425°F. Lightly coat 6 (8-ounce) cocottes or ramekins with cooking spray; set aside. Bring 4 quarts water to a boil in a large pot over high. Add 1/3 cup salt; let water return to a boil. Add broccoli; cook, stirring occasionally, until just tender, about 3 minutes. Drain. Transfer broccoli to a large bowl filled with ice water; let stand 5 minutes. Drain. Arrange broccoli in a single layer on a baking sheet lined with paper towels; pat dry. Transfer broccoli to a large bowl; set aside.

Melt 1/2 cup butter in a large saucepan over medium. Add onion; cook, stirring occasionally, until softened, about 8 minutes. Gradually whisk in flour; cook, whisking constantly, until flour is completely incorporated and lightly browned, about 2 minutes. Gradually whisk in beer and half-and-half; cook, whisking constantly, until sauce thickens and begins to bubble, 3 to 4 minutes. Gradually whisk in cheese, Worcestershire, dry mustard, pepper, and 2 teaspoons salt until smooth.

Pour cheese sauce over broccoli; stir to combine. Season with salt to taste. Spoon mixture evenly into prepared cocottes, and arrange on a rimmed baking sheet.

Microwave remaining 2 tablespoons butter in a medium-size microwavable bowl on HIGH until melted, 30 seconds to 1 minute. Add bread pieces and remaining 1/4 teaspoon salt; toss to coat. Sprinkle mixture evenly over broccoli mixture in cocottes. Bake, uncovered, in preheated oven until bread is golden brown and cheese is bubbly, 16 to 20 minutes.