Sunday dinner: Caramelized onion, steak & Swiss chard panini

Sink your teeth into this hearty panini. A great combo of ingredients, including caramelized onions, gives this sandwich fabulous flavor.

Caramelized onion, steak & Swiss chard panini

This Sunday dinner recipe for caramelized onion, steak and Swiss chard panini isn’t the quickest sandwich to put together, but its wonderful flavor will more than make up for it! The taste of caramelized onions can make a great addition to so many dishes, and this panini is one of them.

Don’t be nervous about making caramelized onions. It’s a super-simple process that basically only requires a hot skillet and some time. Once you make them, I guarantee you’ll discover many ways to use them! For this dish, the sweet and rich onions are a perfect complement to the steak, and the Swiss chard leaves are good to use with this recipe because they’re hearty. Let’s not forget the mayonnaise-horseradish spread. It adds just the right touch to this panini.

Caramelized onion, steak & Swiss chard panini

No panini press? No problem! Learn how to create a DIY panini-style press with a few canned goods and an extra skillet

Caramelized onion, steak & Swiss chard panini recipe

Serves 2


  • 3 tablespoons mayonnaise
  • 1 teaspoon horseradish sauce
  • 1 white onion, cut into thin strips
  • 1/4 teaspoon salt
  • 3/4 pound thin-cut beef round steaks
  • 1 tablespoon vegetable oil
  • 1/4 teaspoon salt
  • 1/4 teaspoon ground black pepper
  • 4 (1-1/2 inch thick) slices hearty sandwich bread
  • 3 tablespoons butter, divided
  • 3 Swiss chard leaves, washed and dried
  • 4 ounces shredded mozzarella cheese


  1. Add the mayonnaise and horseradish sauce to a small bowl. Whisk together, taste and adjust the flavor as needed. Refrigerate until ready to use.
  2. Caramelize the onions by adding 1 tablespoon of the butter to a skillet over medium heat. When hot, add the onions and stir.
  3. Let the onions cook, stirring every 5-10 minutes, for about 30-40 minutes (this process could take more time, or less time). The color change of the onions will go from translucent to light golden, and finally to a dark, caramelized color. During the cooking process, you may need to lower the heat slightly.
  4. Once caramelized, add 1/4 cup of water to the pan to help loosen the pieces stuck to the bottom. Scrape the bottom of the pan, stirring, until the water evaporates. This process is called deglazing.
  5. Add the salt to the onions, stir and set them aside.
  6. As the onion is cooking, season the steak with the salt and ground black pepper.
  7. Add the oil to a large skillet over medium heat. When hot, add the steak and cook on each side, for 3-4 minutes.
  8. Remove the steak, allow it to sit for several minutes, then cut it into 1-inch strips.
  9. Preheat a panini press to 375 degrees F, and set it to medium-high heat.
  10. Butter 1 side of each bread slice. Flip 2 over onto a clean surface, and spread each with the mayonnaise-horseradish spread.
  11. Evenly divide the steak slices, and place them on the 2 slices of bread with the mayonnaise-horseradish spread.
  12. Evenly divide the caramelized onions and add them over the steak.
  13. Add 1-1/2 Swiss chard leaves over each sandwich, then evenly divide the cheese and add to each.
  14. Cover the sandwiches with the remaining bread, buttered side up.
  15. Add the sandwiches to the panini griddle and close the press. Cook for 3-4 minutes, or until the cheese melts and the bread is toasted on both sides.
  16. Remove from the griddle, slice diagonally with a serrated knife and serve warm.

Sink your teeth into this flavorful sandwich!

More Sunday dinner recipes

Thai red curry shrimp with green beans
Parmesan-crusted baked pork medallions
Baked pasta with Sriracha cream sauce