Beef with Caramelized Onions
Tender strips of beef paired with deeply sweet, slow-cooked caramelized onions make for an irresistibly savory and comforting main dish.
Ingredients
- •1.5 lbs flank steak or sirloin, thinly sliced against the grain (680g)
- •3 large yellow onions, thinly sliced
- •3 tablespoons olive oil, divided
- •3 cloves garlic, minced
- •2 tablespoons balsamic vinegar
- •1 tablespoon low-sodium soy sauce
- •1/2 cup beef broth (120ml)
- •1 teaspoon fresh thyme leaves
- •1/2 teaspoon kosher salt
- •1/4 teaspoon freshly ground black pepper
Instructions
- 1
Heat 2 tablespoons of olive oil in a large skillet over medium heat and add the sliced onions, stirring frequently until they begin to soften.
- 2
Reduce the heat to medium-low and cook the onions for 20 to 25 minutes, stirring occasionally, until they are deeply golden brown and caramelized.
- 3
Stir the minced garlic and fresh thyme into the onions during the last minute of caramelization until fragrant, then remove the onions from the skillet and set them aside.
- 4
Pat the sliced beef dry with paper towels and season with kosher salt and black pepper.
- 5
In the same skillet, heat the remaining 1 tablespoon of olive oil over high heat until shimmering.
- 6
Add the beef in a single layer without overcrowding the pan, searing for 2 minutes without moving so a nice crust forms, then stir and cook for another 1 to 2 minutes until just cooked through.
- 7
Pour in the balsamic vinegar, soy sauce, and beef broth, scraping up any browned bits from the bottom of the skillet.
- 8
Return the caramelized onions to the skillet with the beef, tossing everything together and simmering for 2 minutes until the sauce slightly reduces and coats the meat.
- 9
Serve warm, garnished with extra fresh thyme if desired.
💡 Chef tips
- For even deeper flavor, you can caramelize the onions a day in advance and store them in the refrigerator until you are ready to cook the beef.
- If the onions start to dry out or stick to the pan while caramelizing, add a tablespoon of water at a time to deglaze the pan.
- Leftovers can be stored in an airtight container in the refrigerator for up to 3 days and reheat wonderfully in a skillet over medium heat.
✅ How it should turn out
The finished dish features melt-in-your-mouth tender beef bathed in a glossy, rich sauce infused with the sweet, deep flavor of perfectly caramelized onions and a subtle tang from the balsamic vinegar.