# How to Make It:
01 - Combine flour, cornstarch, salt, pepper, and paprika in a shallow bowl. Place buttermilk in a separate bowl for dipping.
02 - Dip onion slices in buttermilk, then dredge through the flour mixture. Shake off excess coating before frying.
03 - Heat 1 inch of vegetable oil in a skillet over medium-high heat. Fry onions in batches for 2-3 minutes until golden brown. Drain on paper towels.
04 - Spread softened butter on one side of each bread slice. Place two slices butter-side down on your work surface.
05 - Distribute half the cheddar and mozzarella over each slice. Top with crispy fried onions, then remaining cheese. Cover with second bread slice, butter-side up.
06 - Cook on a nonstick skillet or griddle over medium-low heat for 3-4 minutes per side. Press gently until bread turns golden brown and cheese melts completely.
07 - Remove from heat, let rest for 1 minute, cut diagonally, and serve immediately.