Il Crostino Palermitano
Rosticceria at Home: After-School Snacks & Palermo Street Food
In Palermo, the after-school rush runs on hot peanut oil and melted cheese. The undisputed king of the rosticceria case is the crostino, an unapologetic, deep-fried sandwich that leaves the French Croque Monsieur in the dust. The secret to keeping the molten center from blowing out in the fryer is pure grandmotherly engineering: a hyper-dense béchamel sauce and a cheap, impenetrable flour-and-water batter called a lega. Prep the béchamel the night before, and you'll be eating the genuine article in twenty minutes.
Before you start
Make the béchamel ahead of time.
You can make the béchamel up to three days in advance and keep it tightly covered in the refrigerator. A cold, stiff sauce is exactly what you want when building the sandwiches.
Ingredients
- unsalted butter3 1/2 tbsp
- all-purpose flour1/2 cup
- all-purpose flour1 tbsp
- whole milk2 cup
- kosher salt1/2 tsp
- nutmeg1/4 tsp
- Parmigiano-Reggiano1/4 cup
- white sandwich bread10 large
- deli ham1/4 lb
- low-moisture mozzarella1/4 lb
- all-purpose flour1 1/2 cup
- cold water1 3/4 cup
- fine unseasoned breadcrumbs2 cup
- peanut oil2 qt
Method
- 01
Build the dense béchamel.
Melt the butter in a saucepan over medium-low heat. Whisk in the half cup plus one tablespoon of flour and toast for 1 to 2 minutes until it smells slightly nutty. Slowly pour in the warm milk, whisking constantly to prevent lumps, then add the salt and nutmeg. Cook for 5 to 7 minutes until the sauce is exceptionally thick and paste-like. Remove from heat, stir in the Parmigiano, and let it cool completely.
- 02
Mix the filling.
Fold the finely diced ham and low-moisture mozzarella directly into the completely cooled béchamel. Mixing the filling directly into the sauce ensures an even bind, keeping the cheese locked inside during frying.
- 03
Assemble and seal the sandwiches.
Lay out the crustless bread. Spread a thick layer of the béchamel mixture onto half the slices, leaving a half-inch bare border around the edges. Top with the remaining bread, firmly pressing the bare edges together with your fingers to seal. Cut each sandwich diagonally into two triangles.
- 04
Prepare the lega batter.
In a medium bowl, whisk together the remaining one and a half cups of flour and the cold water until smooth. It should resemble a thin pancake batter. Place the fine breadcrumbs in a separate shallow dish.
- 05
Bread the crostini.
Dip each sandwich triangle completely into the wet lega batter, making sure the cut edges are fully coated. Let the excess drip off, then immediately drop it into the breadcrumbs. Press the crumbs firmly into the bread, packing them tightly around the pinched edges to form your protective armor.
- 06
Fry to a golden crisp.
Heat about 2 inches of peanut oil in a Dutch oven to 350F. Fry the crostini in small batches for 2 to 3 minutes per side until deeply golden brown. Transfer to a wire rack or paper towels to drain. Let them sit for exactly 5 minutes before eating so the molten cheese can set up into the perfect, stretchy pull without burning your mouth.
Notes
Respect the cheese rule.
Do not substitute fresh mozzarella packed in water. The steam it creates in the hot oil will violently blow out the sides of your perfectly sealed crostino, ruining the oil and the sandwich. Stick to low-moisture pizza mozzarella.
Fry straight from the freezer.
You can assemble and bread the crostini, freeze them solid on a sheet pan, and transfer to a zip-top bag. Fry straight from frozen at a slightly lower temperature (340F) for an extra 2 to 3 minutes.