This is a beef burger topped with melted Brie and slow-cooked caramelized onions on a toasted brioche bun. It takes about an hour start to finish, and most of that time is hands-off onion cooking. The real reason to make it: the combination of creamy Brie and sweet-savory onions does a lot of the flavor work for you, so the burger tastes impressive without requiring any unusual skill.
The short version of why this works
Two things carry this recipe. First, the onions need the full 20–25 minutes over medium heat — rushing them on high heat gives you soft onions, not caramelized ones. The sugar and balsamic go in at the end, not the beginning, so the onions build their own sweetness first and the vinegar just sharpens it. Second, the Brie goes on in the last minute with a lid on the pan. Brie melts fast and unevenly if you leave it exposed to direct heat; trapping steam does the job gently and keeps it from pooling off the patty. Remove the rind before slicing — it won’t melt and turns rubbery under heat.
Troubleshooting
- Onions burning before they caramelize: Your heat is too high or the pan is too dry. Drop to medium-low and add a small splash of water — it deglazes the fond and keeps the onions moving without adding fat.
- Patties puffing up in the middle: Press a shallow thumbprint into the center of each raw patty before it hits the heat. The center cooks up level instead of doming, which matters when you’re stacking Brie and onions on top.
- Brie sliding off the patty: Let the patties rest on the bun bottom for 30 seconds before piling on the onions. The cheese firms up slightly as it cools and grips better.
- Brioche bun going soggy: Toast the cut sides until they’re genuinely golden, not just warm. A firm toasted surface resists the moisture from the onions far longer than a lightly warmed bun.
- Cooking for a crowd and onions going cold: Make the onion batch up to two days ahead and refrigerate. Reheat in a skillet over low heat while the patties cook — they come back perfectly and free up your attention for the grill.
Leftovers and meal prep
Cooked patties keep in the fridge for up to 3 days in an airtight container. Reheat them in a covered skillet over medium-low with a tablespoon of water — the steam warms them through without drying out the beef. Skip the microwave; it toughens the meat. The caramelized onions are the real meal-prep win here: they refrigerate well for 4–5 days and freeze for up to 2 months in a small zip-lock bag. Make a double or triple batch of onions on a Sunday and you’re halfway done next time you want these. Assembled burgers don’t store well — keep the components separate and build fresh. Ground beef patties (raw) can be frozen between sheets of parchment for up to 3 months; thaw overnight in the fridge before cooking and always cook ground beef to an internal temperature of 160°F (71°C).
French Brie and Caramelized Onion Burger
Ingredients
Main Ingredients
- 500 grams ground beef preferably grass-fed for richer flavor
- 1 cup brie cheese rind removed, sliced
- 4 slices brioche buns lightly toasted
For Caramelized Onions
- 2 large yellow onions thinly sliced
- 2 tablespoons butter unsalted
- 1 tablespoon olive oil extra virgin for depth
- 1 teaspoon sugar to enhance sweetness
- 1 tablespoon balsamic vinegar for acidity balance
- 1 pinch salt to taste
- 1 pinch freshly ground black pepper to taste
Instructions
- Begin by caramelizing the onions. In a large skillet over medium heat, melt 2 tablespoons of unsalted butter with 1 tablespoon of olive oil.
- Add the thinly sliced yellow onions and a pinch of salt. Sauté for 20-25 minutes, stirring occasionally, until they turn a deep golden brown. Add 1 teaspoon of sugar to enhance sweetness and a tablespoon of balsamic vinegar for acidity. Cook for an additional 5 minutes, then set aside.
- While the onions caramelize, form the patties. In a bowl, combine 500 grams (1.1 pounds) of ground beef with salt and freshly ground black pepper to taste. Form into four equal patties.
- Preheat a grill or skillet over medium-high heat. Cook the patties for about 4-5 minutes on each side for medium-rare, adjusting the time based on your preferred doneness.
- In the final minute of cooking, place a slice of Brie cheese on each patty and cover the pan to melt the cheese gently.
- To assemble, place the patties with melted Brie onto the bottom half of each toasted brioche bun. Generously top with caramelized onions and finish with the bun top.
Notes
Nutrition
FAQ
Can I make the caramelized onions ahead of time?
Yes — they’re actually better made a day or two ahead. Store them in a sealed container in the fridge for up to 5 days and reheat gently in a skillet before serving. This is the single best thing you can do if you’re cooking these burgers for a group.
What’s the best way to cook the patties for medium doneness without a thermometer?
Use a thermometer if you can — ground beef needs to reach 160°F (71°C) internal temperature for food safety, and that’s not something you can reliably judge by touch or color alone. A basic instant-read thermometer costs under $15 and removes all the guesswork, especially when you’re cooking multiple patties at once.
Can I use a different cheese if I can’t find Brie?
Camembert is the closest swap — same soft-ripened style, similar melt, slightly earthier flavor. Fontina also works well and melts cleanly. Skip the egg in the mix — it makes the patty mushy, and the same logic applies here: don’t substitute a hard cheese like cheddar expecting the same result, because it won’t give you that creamy layer.
How do I scale this up for 8 or 12 burgers without everything getting cold?
Cook the onions in one big batch — they hold well in a covered pan on the lowest heat setting for 20–30 minutes. Stagger the patties in two or three rounds on the grill and tent finished ones loosely with foil; they stay hot enough to melt the Brie when you add it just before serving.
Can I grill these instead of using a skillet?
Yes, a grill works well for the patties. The challenge is melting the Brie — cover the grill for the last minute after adding the cheese, just as you would cover a pan. Make sure your grill grates are clean and well-oiled so the patties don’t stick and fall apart when you flip them.