Broccoli Rabe Gratin - Challenge Dairy

Ingredients

• 6 Tablespoons Challenge Butter, plus more for greasing pan
• kosher salt
• 3 bunches (2 ½ pounds) broccoli rabe, tough stems removed, roughly chopped
• ½ cup breadcrumbs
• 1 ½ cups grated parmesan, divided
• 2 Tablespoons minced fresh thyme
• freshly ground black pepper
• 2 garlic cloves, minced
• 3 Tablespoons all-purpose flour
• 1 cup whole milk
• 1 cup heavy cream