Creamy Broccoli Cheddar Casserole

Ingredients

• 2 1/2 cups all-purpose flour, plus more as needed and for a worksurface
• 2 1/4 teaspoons instant yeast
• 3/4 cup warm water
• 4 tablespoons salted butter, melted, divided
• 1/4 cup baking soda
• 1 egg, beaten
• pretzel salt, to taste, for sprinkling
• 1 clove garlic, grated
• 2 tablespoons fresh thyme leaves
• 3 tablespoons extra-virgin olive oil
• 1 tablespoon salted butter
• 1 yellow onion, chopped
• 1/4 cup all-purpose flour
• 3 cloves garlic, chopped
• 1 teaspoon paprika
• cayenne, to taste
• 3 cups low-sodium vegetable broth or chicken broth
• 4 cups broccoli florets, chopped
• kosher salt, to taste
• black pepper, to taste
• 2 cups whole milk
• 2 1/2 cups sharp cheddar cheese, shredded