Save to Pinterest Last winter, during a particularly gray afternoon, I found myself craving something outrageously comforting. I had a bag of onions staring at me from the counter and an almost-empty cheese drawer. On a whim, I decided to fry up those onions and sandwich them between layers of cheese. The smell of caramelizing onions filled the kitchen, and when that first bite hit—crunch meeting melty bliss—I knew I'd stumbled onto something special.
I made these for my sister when she was having a particularly rough week at work. We stood around the kitchen island, eating them directly off the cutting board, too impatient to bother with plates. She took one bite, looked at me with wide eyes, and said 'You need to write this down.' That's usually how I know a recipe is a keeper.
Ingredients
- Small yellow onion: Yellow onions have the perfect sweetness balance for frying—red onions can be too sharp, and sweet onions might caramelize too quickly
- Buttermilk: This creates a tangy, tender coating that clings beautifully to the onions
- Cornstarch: The secret to extra-crispy results—combining it with flour gives you that shatteringly crunch we're after
- Sharp cheddar: Bold flavor stands up to the rich fried onions without getting lost
- Mozzarella: Provides that gorgeous cheese pull and melts like a dream
- Sourdough bread: Sturdy enough to hold everything together, and the tang complements the sweet onions perfectly
Instructions
- Create your crispy onion magic:
- Whisk together the flour, cornstarch, salt, pepper, and paprika in a shallow bowl until everything's well combined. Pour your buttermilk into a separate bowl. Dip those thin onion slices into the buttermilk, letting any excess drip off, then press them into the flour mixture. Shake off the loose powder—you want a light coating, not a heavy batter.
- Fry until golden:
- Heat about an inch of vegetable oil in your skillet until it shimmers and a tiny bit of onion sizzles immediately upon contact. Fry the onions in batches, turning once, until they're deeply golden and smell amazing. Drain them on paper towels and resist the urge to snack on them all before assembling.
- Build your masterpiece:
- Butter one side of each bread slice generously. Place two slices butter-side down and sprinkle them with half of both cheeses. Pile on those crispy fried onions like you mean it, then add the remaining cheese. Top with the remaining bread, butter-side facing up.
- Grill to perfection:
- Heat a clean skillet or griddle over medium-low heat—you want it low enough that the cheese melts before the bread burns. Cook each sandwich for about 3-4 minutes per side, pressing down gently with your spatula. When both sides are golden brown and crisp, and you can see cheese starting to ooze out the sides, you're done.
Save to Pinterest This sandwich has become my go-to for rainy Saturdays and comfort-food emergencies. Something about the combination of warm, crispy, cheesy, and just a bit messy makes everything feel right with the world.
Making It Ahead
You can fry the onions up to a day ahead and store them in an airtight container—they'll stay surprisingly crispy. When you're ready to eat, just assemble and grill as usual. The onions will re-crisp beautifully in the hot pan.
Getting Creative
Sometimes I'll add a thin layer of Dijon mustard to the bread before building the sandwich—it cuts through the richness beautifully. A few slices of tomato work wonders too, adding bright acidity and moisture.
Serving Suggestions
A hot bowl of tomato soup is the obvious pairing, but honestly, these are substantial enough to stand alone. A crisp green salad with a vinaigrette helps balance all that cheesy goodness.
- Cut sandwiches diagonally—the classic presentation somehow makes them taste better
- Let them rest for about a minute before cutting so the cheese sets slightly
- Have napkins ready, because crispy onions will absolutely escape while eating
Save to Pinterest There's something deeply satisfying about taking a classic we all know and love and giving it this little upgrade. Enjoy every crunchy, cheesy bite.
Recipe Questions & Answers
- → Can I use store-bought crispy onions instead of making them from scratch?
Yes, store-bought crispy fried onions work perfectly as a shortcut and will save you about 15 minutes of prep time. Just use about 1 cup of store-bought onions to match the quantity in this version.
- → What type of bread works best for this?
Sourdough bread provides excellent structure and tangy flavor that complements the rich cheese. White bread, Texas toast, or even potato bread also work well. Avoid very soft bread that might fall apart under the weight of the toppings.
- → Can I make the crispy onions ahead of time?
Absolutely! Prepare the crispy onions up to 2 days in advance and store them in an airtight container at room temperature. They may lose a bit of crunch but will still add great texture and flavor to your sandwich.
- → What cheese combination works best?
The sharp cheddar provides bold flavor while mozzarella delivers the perfect melt. You can substitute gruyère for extra nuttiness, add Monterey jack for more melt, or swap in pepper jack if you enjoy some heat.
- → How do I prevent the sandwich from getting soggy?
Ensure your crispy onions are well-drained on paper towels after frying to remove excess oil. Assemble the sandwich just before cooking, and don't overload with onions. Cooking over medium-low heat allows the cheese to melt completely without burning the bread.
- → What sides pair well with this?
Tomato soup creates the classic comforting combination. A crisp green salad with vinaigrette cuts through the richness, or serve with pickles and potato chips for a casual diner-style meal.