Pin it The smell of frying onions always pulls people into the kitchen, but when you add crispy buttermilk chicken to the mix, it becomes a full-on gathering. I started making this sandwich on a whim one Sunday when I had leftover buttermilk and a craving for something indulgent. The combination of crunchy, sweet onions piled on top of juicy fried chicken with tangy aioli turned into one of those recipes I now make whenever I want to impress without pretending I'm fancy. It's messy, satisfying, and worth every napkin.
I made this for a casual dinner with friends who showed up hungry and skeptical of my cooking skills. Watching them go quiet after the first bite, then immediately reach for seconds, felt like winning something. One friend even asked if I'd stolen the recipe from a restaurant. I hadn't, but I took it as the highest compliment anyway.
Ingredients
- Boneless, skinless chicken thighs: Thighs stay juicier than breasts and handle the marinade beautifully without drying out during frying.
- Buttermilk: The acidity tenderizes the chicken and adds a subtle tang that balances the richness of the breading.
- Garlic powder and paprika: These season the marinade and give the chicken flavor from the inside out, not just on the surface.
- All-purpose flour and cornstarch: The cornstarch makes the breading extra crispy and light, not heavy or doughy.
- Smoked paprika: Adds a gentle smokiness to the breading that makes the chicken taste more complex.
- Yellow onion: Slice it thin so it fries up shatteringly crisp and sweet, almost like onion rings without the batter.
- Mayonnaise: The base of the aioli, creamy and rich enough to cling to the chicken and bun.
- Garlic clove: Fresh garlic in the aioli is sharper and brighter than powder, and it cuts through the fried richness.
- Lemon juice: Brightens the aioli and keeps it from feeling too heavy or one-note.
- Dijon mustard: A small amount adds depth and a tiny bit of sharpness that wakes up the whole sauce.
- Brioche buns: Soft, slightly sweet, and sturdy enough to hold up to all the toppings without falling apart.
- Vegetable oil: For frying, it gets hot without smoking and keeps the flavor neutral so the chicken and onions shine.
Instructions
- Marinate the chicken:
- Whisk together buttermilk, garlic powder, paprika, salt, and black pepper in a bowl, then add the chicken thighs and make sure they're completely submerged. Cover and refrigerate for at least 30 minutes, though a few hours makes them even more tender.
- Prepare the breading:
- In a shallow dish, combine flour, cornstarch, smoked paprika, salt, and black pepper. Mix it well so the spices are evenly distributed and every piece of chicken gets the same flavor.
- Coat the onions:
- Toss thinly sliced onions with flour, salt, and black pepper in a bowl until each piece is lightly coated. Don't overdo it, you want a thin, crispy shell, not a thick crust.
- Fry the onions:
- Heat about an inch of vegetable oil in a large skillet to 350°F, then fry the onions in batches until they're golden and crispy, about 2 to 3 minutes per batch. Drain them on paper towels and resist the urge to snack on all of them before assembly.
- Bread the chicken:
- Remove chicken from the marinade, letting excess buttermilk drip off, then press each thigh firmly into the breading mixture so it sticks. Let them sit for a minute so the coating sets and doesn't fall off in the oil.
- Fry the chicken:
- Fry the chicken in the same hot oil for 5 to 7 minutes per side, until the internal temperature reaches 165°F and the outside is deeply golden. Transfer to a wire rack or paper towels to drain and stay crispy.
- Make the aioli:
- In a small bowl, stir together mayonnaise, minced garlic, lemon juice, Dijon mustard, salt, and pepper. Taste it and adjust the seasoning, it should be tangy, garlicky, and just a little sharp.
- Toast the buns:
- If you want, butter the cut sides of the brioche buns and toast them in a skillet until golden and slightly crisp. This step is optional but adds texture and keeps the buns from getting soggy.
- Assemble the sandwiches:
- Spread aioli generously on both sides of each bun, then layer with lettuce if using, a piece of fried chicken, a big pile of crispy onions, and the top bun. Press down gently and get ready for a messy, delicious bite.
Pin it The first time I served these sandwiches, someone said it tasted like comfort food and a celebration at the same time. I hadn't thought of it that way, but it stuck with me. There's something about the contrast of textures and flavors, crispy, creamy, tangy, savory, that makes it feel like more than just dinner.
Adjusting the Heat
If you like a little kick, stir hot sauce into the aioli or add a pinch of cayenne to the breading mixture. I've done both, and the heat doesn't overpower the sweetness of the onions or the richness of the chicken. It just wakes everything up a little and makes you want another bite.
Swapping the Chicken
Chicken breasts work if you prefer white meat, but they cook faster and can dry out if you're not careful. Pound them to an even thickness before marinating so they cook evenly. I still think thighs are the move here, they're more forgiving and stay juicy even if you fry them a minute too long.
Serving Suggestions
These sandwiches are rich, so I like to serve them with something bright and crunchy on the side. Pickles, coleslaw, or even a simple green salad with a sharp vinaigrette balances the meal without adding more heaviness. Fries are great too, but honestly, the sandwich is filling enough on its own.
- Add a handful of pickles or pickled jalapeños for extra tang and crunch.
- Serve with sweet potato fries or a tangy slaw to balance the richness.
- Wrap the sandwiches in parchment paper for easier handling and less mess.
Pin it This sandwich has become one of those recipes I make when I want to feel like I'm treating myself and whoever I'm feeding. It's indulgent, a little messy, and completely worth it.
Recipe FAQ
- → Can I use chicken breasts instead of thighs?
Yes, chicken breasts work well as a substitute. Reduce the cooking time by 1-2 minutes per side since they're thinner and cook faster. Thighs stay juicier but breasts are leaner if preferred.
- → How long should I marinate the chicken?
Marinate for at least 30 minutes for basic flavor. For deeper seasoning and tenderness, refrigerate up to 4 hours. Avoid overnight marinating as the buttermilk can break down the texture excessively.
- → What temperature should the oil be for frying?
Maintain oil at 350°F (175°C) for optimal results. Too cool and you'll get greasy, soggy coatings; too hot and the exterior burns before the inside cooks. Use a thermometer for accuracy.
- → How do I keep the crispy onions crispy before serving?
Drain fried onions on paper towels immediately after frying to remove excess oil. Add them to the sandwich just before serving to maintain their crunch. Store leftovers in an airtight container.
- → Can I make the aioli ahead of time?
Yes, prepare aioli up to 2 days in advance. Store in an airtight container in the refrigerator. Give it a quick stir before using, as ingredients may separate slightly during storage.
- → What sides pair well with this sandwich?
Pickles, coleslaw, and french fries are classic pairings. The acidic and cool elements balance the rich, savory sandwich beautifully. Roasted vegetables or a simple green salad offer lighter options.