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Glazed Balsamic Steak and Onions Recipe

Glazed Balsamic Steak and Onions

Seared steak is paired with tender onions and a sweet, tangy balsamic glaze for a fast and flavorful dinner. Use sirloin, strip steak, or flank steak, and slice the meat against the grain for the best texture.
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Prep Time 15 minutes
Cook Time 25 minutes
Total Time 45 minutes
Servings: 4 servings
Ingredients Method Notes

Ingredients
  

Steak and Seasoning
  • 1 1/2 pounds Boneless sirloin, strip steak, or flank steak
  • 1 teaspoon Kosher salt, divided
  • 1/2 teaspoon Freshly ground black pepper, divided
  • 2 tablespoons Olive oil, divided
Onions and Glaze
  • 2 large Large yellow onions, thinly sliced
  • 2 cloves Garlic cloves, minced
  • 1/2 cup Balsamic vinegar
  • 2 tablespoons Packed light brown sugar
  • 1 tablespoon Dijon mustard
  • 1 tablespoon Unsalted butter
  • 1 tablespoon Chopped fresh parsley, optional

Method
 

Step-by-Step
  1. Pat the steaks dry. Season both sides with about 3/4 teaspoon kosher salt and 1/4 teaspoon black pepper, then let them stand at room temperature for 15 to 20 minutes.
  2. Whisk the balsamic vinegar, brown sugar, Dijon mustard, remaining salt, and remaining pepper together in a small bowl.
  3. Heat 1 tablespoon olive oil in a large skillet over medium heat. Add the sliced onions and cook for 8 to 10 minutes, stirring occasionally, until softened and lightly browned.
  4. Add the minced garlic and cook for about 30 seconds, just until fragrant. Transfer the onions to a plate.
  5. Add the remaining olive oil to the skillet and increase the heat to medium-high. Sear the steaks for approximately 3 to 5 minutes per side, depending on thickness and desired doneness.
  6. Transfer the steaks to a cutting board and rest for 5 to 10 minutes. For medium-rare, remove the steaks at about 125 to 130°F, allowing the temperature to rise slightly while they rest.
  7. Reduce the skillet heat to medium and pour in the balsamic mixture. Scrape up the browned bits from the bottom and simmer for 2 to 4 minutes, until the glaze is slightly thickened.
  8. Stir in the butter, then return the onions to the skillet. Toss them gently in the glaze until they are glossy and thoroughly coated.
  9. Slice the steak against the grain and arrange it with the balsamic onions and remaining glaze. Garnish with chopped parsley if desired.

Notes

Optional marinating time is 30 minutes to 2 hours. Do not reduce the balsamic glaze too far because it thickens as it cools and may become overly sticky or bitter. For flank or skirt steak, slicing thinly against the grain is essential for tenderness.