This delectable recipe combines creamy spinach dip with warm, crusty bread for a mouthwatering appetizer that’s sure to please any crowd.
- ¼ cup plus 2 tablespoons unsalted butter, divided
- 2 tablespoons all-purpose flour
- ¾ cup whole milk
- ¾ cup heavy whipping cream
- 1 ¼ teaspoons kosher salt, divided
- ¾ teaspoon ground white pepper, divided
- 1 ½ cups chopped yellow onion (from 1 medium [10-ounce] onion)
- 1 (10-ounce) package fresh baby spinach (about 8 cups)
- 14 ounces pre-shredded Parmesan cheese (about 4 1/4 cups)
- 1 (24-ounce) sourdough boule
- 1 tablespoon chopped jarred Calabrian chiles
- 1 ½ ounces pre-shredded low-moisture part-skim mozzarella cheese (about 1/3 cup)
- Preheat the oven to 450°F. Melt 2 tablespoons of the butter in a small saucepan over medium heat. Add flour, whisking until fully incorporated, about 1 minute. Gradually drizzle in milk and cream, whisking constantly, until fully incorporated and no lumps remain. Bring to a boil over medium, whisking constantly; boil, undisturbed, for 1 minute. Reduce heat to low and simmer, stirring occasionally, until thickened, about 20 minutes. Stir in 3/4 teaspoon of the salt and 1/4 teaspoon of the white pepper. Remove from heat.
- While the milk mixture simmers, melt the remaining 1/4 cup butter in a large Dutch oven over medium heat. Stir in the onion and cook, stirring occasionally, until translucent, about 6 minutes. Add spinach and cook, stirring often, until liquid has evaporated and the pot is dry, about 4 minutes.
- Pour the milk mixture into the spinach mixture in the Dutch oven; stir to combine. Stir in Parmesan and the remaining 1/2 teaspoon each of salt and pepper. Remove from heat.
- Cut the sourdough boule crosswise into 5 (1-inch-thick) slices, cutting through the bread almost completely but leaving the bottom crust intact. Slice the boule lengthwise down the center so each slice is halved but the bottom crust is intact. Place the boules on a large, rimmed baking sheet lined with parchment paper or aluminum foil. Spoon the spinach-Parmesan mixture evenly between bread slices, and top evenly with calabrian chiles. Sprinkle evenly with mozzarella.
- Bake in a preheated oven until the top is browned and the center is hot and gooey, 7 to 10 minutes.