# What You'll Need:
→ Crispy Onions
01 - 1 small yellow onion, thinly sliced
02 - 1/2 cup all-purpose flour
03 - 1/4 cup cornstarch
04 - 1/2 teaspoon salt
05 - 1/2 teaspoon black pepper
06 - 1/2 teaspoon paprika
07 - 1/2 cup buttermilk (or milk with a splash of lemon juice)
08 - Vegetable oil, for frying
→ Sandwich
09 - 4 slices sourdough or white bread
10 - 4 tablespoons unsalted butter, softened
11 - 1 cup grated sharp cheddar cheese (about 100 grams)
12 - 1 cup grated mozzarella cheese (about 100 grams)
# Method:
01 - In a shallow bowl, mix flour, cornstarch, salt, pepper, and paprika. In a separate bowl, pour the buttermilk. Dip onion slices into buttermilk, then coat with the flour mixture, shaking off any excess.
02 - Heat 1 inch of vegetable oil in a skillet over medium-high heat. Fry onions in batches until golden and crispy, about 2 to 3 minutes per batch. Drain on paper towels and set aside.
03 - Butter one side of each bread slice. Place two slices buttered side down on a clean surface. Sprinkle half the cheddar and mozzarella evenly over each slice. Add a generous layer of crispy onions, then top with remaining cheese. Cover with the other bread slices, buttered side up.
04 - Heat a nonstick skillet or griddle over medium-low heat. Cook sandwiches for 3 to 4 minutes per side, pressing gently, until the bread is golden brown and cheese is melted.
05 - Remove sandwiches from skillet, let rest briefly, then cut in half and serve while hot.