Pin It The first time I made crispy onions from scratch, my entire apartment smelled like a state fair and I couldnt stop eating them straight from the paper towels. These sandwiches started as a happy accident when I had leftover fried onions and needed to use up some aging sourdough. Now theyre my go-to comfort food when regular grilled cheese just wont cut it.
My roommate walked in while I was frying the onions and immediately asked what special occasion I was cooking for. I had to explain that sometimes a Tuesday night just deserves something extra indulgent. Now whenever either of us has a rough day, we give each other that knowing look that means crispy onion grilled cheese night.
Ingredients
- 1 small yellow onion: Thinly sliced, this creates the foundation for that crave-worthy crunch factor
- 1/2 cup all-purpose flour: The base of your crispy coating that turns golden and irresistible
- 1/4 cup cornstarch: The secret ingredient that makes the coating extra light and crispy
- 1/2 teaspoon salt and black pepper each: Essential seasoning that makes the onions addictive on their own
- 1/2 teaspoon paprika: Adds a subtle warmth and beautiful golden color to the fried onions
- 1/2 cup buttermilk: Helps the flour mixture stick to the onions and adds a tangy depth
- Vegetable oil: For frying until perfectly crispy and golden brown
- 4 slices sourdough or white bread: Sturdy enough to hold all those fillings without getting soggy
- 4 tablespoons unsalted butter: Spread on the outside for that classic golden crunch
- 1 cup sharp cheddar cheese: Grated fresh for the best melt and bold flavor
- 1 cup mozzarella cheese: Grated fresh for that incredible stretch factor
Instructions
- Make the crispy onions:
- In a shallow bowl, whisk together flour, cornstarch, salt, pepper, and paprika until well combined. Pour buttermilk into a separate bowl. Dip each onion slice into the buttermilk, letting excess drip off, then press into the flour mixture to coat thoroughly. Shake off any extra coating so they fry up light and crisp.
- Fry until golden:
- Pour about 1 inch of vegetable oil into a large skillet and heat over medium-high until shimmering. Fry the coated onions in batches for 2 to 3 minutes until they turn a deep golden brown. Transfer to paper towels to drain and season immediately with a pinch of salt.
- Prep your bread:
- Spread softened butter generously on one side of each bread slice. You want complete coverage for that perfect golden crunch. Lay two slices butter-side down on your work surface, ready for building.
- Layer it up:
- Divide half the cheddar and mozzarella between the two butter-side-down slices, spreading evenly to the edges. Pile on a generous layer of those crispy fried onions, then top with the remaining cheese. Place the remaining bread slices on top, butter-side facing up.
- Grill to perfection:
- Heat a nonstick skillet or griddle over medium-low heat. Place sandwiches in the pan and cook for 3 to 4 minutes per side, pressing gently with your spatula, until the bread is deeply golden and the cheese is completely melted.
- Rest and serve:
- Let the sandwiches rest on a cutting board for about 1 minute so the cheese sets slightly. Cut each sandwich in half diagonally and serve while still hot and melty.
Pin It Last winter my sister came over feeling pretty low after a tough week at work, and I made these without saying much. She took one bite and literally stopped mid-sentence, eyes wide, and said this was exactly what she needed but didnt know she wanted.
The Cheese Strategy
Ive learned that grating your own cheese makes a huge difference in how well it melts. Pre-shredded cheese has anti-caking agents that can make your sandwich grainy or prevent proper melting. Take the extra two minutes to grate it fresh and youll taste the difference immediately.
Make-Ahead Magic
The crispy onions can be made up to two days in advance and stored in an airtight container at room temperature. They actually stay surprisingly crispy, and having them ready means you can throw these sandwiches together in about ten minutes on busy weeknights.
Serving Ideas
A simple side of tomato soup turns this into a complete meal that feels like childhood but tastes way more sophisticated. A crisp green salad with vinaigrette cuts through all that rich cheese perfectly if you want something lighter on the side.
- Add a swipe of Dijon mustard to the inside of the bread for a tangy kick that cuts through the richness
- A few thin tomato slices add moisture and freshness between all that cheese and crunch
- For the ultimate shortcut, store-bought fried onions work surprisingly well in a pinch
Pin It Sometimes the simplest comfort foods just need a little twist to become something youll crave forever.
Recipe Questions & Answers
- → Can I use store-bought fried onions instead of making them from scratch?
Yes, store-bought crispy fried onions work perfectly as a time-saving shortcut. They'll still provide that essential crunch and savory flavor, though homemade ones offer slightly fresher taste and texture control.
- → What type of bread works best for this grilled cheese?
Sourdough bread provides excellent structure and tangy flavor that complements the rich cheese. White bread, brioche, or Texas toast also work well. Avoid very soft bread that might become soggy from the cheese and onions.
- → Can I make the crispy onions ahead of time?
Absolutely. Prepare the fried onions up to 2 days in advance and store in an airtight container at room temperature. Re-crisp them in a 350°F oven for 3-5 minutes before assembling for maximum crunch.
- → What other cheeses can I use besides cheddar and mozzarella?
Gruyère adds nutty depth, Swiss provides mild creaminess, provolone offers excellent melt, or pepper jack brings subtle heat. The key is using cheeses that melt well while balancing the sweet-savory onions.
- → How do I prevent the sandwich from getting soggy?
Ensure your crispy onions are well-drained on paper towels to remove excess oil. Don't overload with onions, and cook over medium-low heat to allow cheese to melt evenly without burning the bread before the center warms through.
- → Can I add other ingredients to customize the flavor?
Dijon mustard cuts through the richness, sliced tomatoes add acidity and moisture, caramelized mushrooms deepen the umami, or crisp bacon provides smoky contrast. Keep additions minimal to maintain structural integrity.