Ingredients
Method
- Prep the onions: Slice the onions into uniform half-moons, about ¼-inch thick. Uniformity ensures they cook evenly. Remove any tough outer layers or roots that didn't slice cleanly.
- Combine fats and aromatics: In a large skillet (preferably stainless steel or cast iron for better browning), combine the butter and olive oil over medium-low heat. The olive oil raises the smoke point of the butter, preventing it from burning too quickly. Add the sliced onions, salt, pepper, and thyme. Toss well to coat every slice in the fat.
- The slow roast: Cook the onions undisturbed for about 10 minutes. Do not stir during this phase; you want them to develop a deep golden crust on the bottom. After 10 minutes, reduce heat to medium-low and begin stirring occasionally, scraping up any browned bits from the bottom of the pan.
- Watch for browning: Continue cooking for another 20–30 minutes, stirring every few minutes. The onions will shrink significantly and turn a deep amber color. Watch closely during the last 5 minutes as the milk solids in the butter begin to toast. They should smell nutty and rich, not burnt.
- Finish: Remove from heat immediately once the onions are soft, caramelized, and the butter has turned a golden-brown hue with dark specks (the toasted milk solids). Transfer to a serving dish and sprinkle with flaky sea salt while still hot to help it adhere. Serve immediately.
Nutrition
Notes
These dry-roasted brown butter onions have earned a permanent spot in my rotation. The key is letting the milk solids toast without burning them while the onions soften completely. A pinch of flaky salt at the end makes all the difference, turning simple ingredients into something deeply savory and rich.