1 hour serves 4-6

Sirloin Steak Sandwich With Vidalia Onion Gratin

This is best made with in-season Vidalia onions, one of our favorite early summer produce arrivals, usually showing up in late April. You can make this recipe with other onions but it won’t have the delicate and sweet taste that Vidalias deliver. 

ACTIVE: 10 min. PASSIVE: 50 min. DIFFICULTY Easy


  • 1 8 OZ Pre sirloin steak
  • 1/2 t kosher salt
  • 2 C Vidalia onions, peeled & quartered
  • 2 C Hellman’s mayonnaise
  • 2 C shredded Swiss cheese
  • 1 T freshly grated parmesan cheese
  • 1 10 inch French baguette
  • 1/2 t olive oil
  • Food Processor
  1. Preheat oven to 325°F.
  2. Pulse onions in food processor until finely chopped and slightly pulpy.
  3. Strain off any liquid from the onions using a slotted spoon or colander.
  4. Place onions, mayonnaise, and cheese in a bowl and mix to combine evenly.
  5. Transfer mixture to a 9x11 baking dish.
  6. Sprinkle parmesan over the top of the gratin and bake for 45 minutes.
  7. Remove and let stand for at least 5 minutes before serving. Leftovers keep in the refrigerator for up to a week.
  8. While onion gratin is cooking, tenderize each sirloin steak, rub with a few drops of cooking oil and season with kosher salt. Set aside until ready to cook.
  9. Cut baguette in half horizontally and brush both sides with olive oil.
  10. Prepare grill and cook steaks to desired doneness, let rest for 5 minutes. While steaks are resting, grill bread on the cooler section of the grill until lightly toasted.
  11. Spread a generous layer of onion gratin on the bottom piece of each bread. Cut steak thinly against the grain and divide among the sandwiches. Top with remaining bread and wrap sandwich tightly in foil, let rest for 10 minutes.
  12. When ready to serve, unwrap sandwich and cut into slices with a serrated knife. Secure each sandwich with toothpicks if you have them.


Sirloin Steak Sandwich With Vidalia Onion Gratin

Amount per 239g

  • 239g

    1 serving
  • 626kcal

  • 28.23g

  • 690mg

  • 1.5g

  • 23.2g

  • 30.83g

  • 7.19g


Nutrition is approximate, data retrieved from happyforks.com

Recipe developed by   Jennifer Borchardt