# What You 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 lemon juice)
08 - Vegetable oil for frying
→ Sandwich Assembly
09 - 4 slices sourdough or white bread
10 - 4 tablespoons unsalted butter, softened
11 - 1 cup grated sharp cheddar cheese
12 - 1 cup grated mozzarella cheese
# How to Make It:
01 - Combine flour, cornstarch, salt, pepper, and paprika in a shallow bowl. Pour buttermilk into a separate bowl.
02 - Dip onion slices into buttermilk, then press into flour mixture. Shake off excess coating and transfer to a plate.
03 - Heat 1 inch vegetable oil in a large skillet over medium-high heat until shimmering. Fry onions in batches for 2–3 minutes until golden brown and crispy. Drain on paper towels.
04 - Butter one side of each bread slice generously.
05 - Place two bread slices butter-side down. Distribute half the cheddar and mozzarella evenly over each slice.
06 - Layer a generous amount of fried crispy onions over the cheese on each sandwich.
07 - Top with remaining cheese, then cover with remaining bread slices, butter-side up.
08 - Heat a nonstick skillet or griddle over medium-low heat. Cook sandwiches for 3–4 minutes per side, pressing gently with a spatula, until bread turns golden brown and cheese melts completely.
09 - Transfer sandwiches to a cutting board. Let rest for 1 minute, then cut diagonally and serve immediately.