Crispy Onion Grilled Cheese (Printable)

A decadent sandwich featuring golden crispy fried onions nestled between layers of gooey melted cheese and toasted bread.

# What You’ll Need:

→ For the 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

→ For the Sandwich

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 Steps:

01 - In a shallow bowl, combine flour, cornstarch, salt, pepper, and paprika. Place buttermilk in another bowl. Dip onion slices in buttermilk, then dredge in the flour mixture, shaking off excess.
02 - Heat 1 inch of vegetable oil in a skillet over medium-high heat. Fry onions in batches until golden and crispy, about 2–3 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.
04 - Sprinkle half the cheddar and mozzarella evenly over each slice. Top with a generous layer of crispy onions, then the remaining cheese. Cover with the other bread slices, buttered side up.
05 - Heat a nonstick skillet or griddle over medium-low heat. Cook sandwiches 3–4 minutes per side, pressing gently, until bread is golden brown and cheese is melted.
06 - Remove from skillet, let rest briefly, then cut in half and serve hot.

# Expert Hints:

01 -
  • The contrast between crispy fried onions and gooey melted cheese hits every texture you didn't know you needed.
  • It's deceptively simple to make but tastes like you've been perfecting it for years.
  • Your kitchen will smell incredible while it cooks, and people will ask what you're making before they even see it.
02 -
  • Don't skip the paper towel step when draining onions—excess oil will make them soggy and won't crisp up properly in the sandwich.
  • Medium-low heat is crucial for the sandwich itself; too high and the bread burns before the cheese melts inside.
  • Room-temperature softened butter spreads like a dream, while cold butter tears the bread and leaves gaps where cheese can escape.
03 -
  • Use a cast iron skillet or griddle if you have one—the heat distribution is more even, and your bread will brown more uniformly and beautifully.
  • The butter on the outside doesn't need to be thick; a thin, even layer is all you need for golden, crispy bread without it becoming greasy.
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