A steak sandwich with caramelized onions piles thin slices of seared beef onto crusty Turkish bread with jammy onions, garlic mayo, juicy tomato and peppery arugula, and it is a far cry from a quick deli sandwich.
The onions are cooked low and slow in butter until they turn deep golden, then finished with brown sugar and balsamic vinegar for a sweet, tangy jam. The garlic mayo rests while they cook so the flavors blend, and the steak takes only a few minutes in a hot pan. Set aside about 90 minutes in total, and most of that time is hands off.
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Why This Steak Sandwich with Caramelized Onions Recipe Works
Cooking the onions for 40 minutes over medium low heat, first covered and then uncovered, softens them completely and lets their natural sugars brown. A little brown sugar and balsamic vinegar finish them into a rich, spreadable jam.
Resting the garlic mayo for at least 30 minutes mellows the raw garlic bite and lets it infuse the mayonnaise. It adds a creamy, savory layer that holds the sandwich together.
Searing the steak hard and slicing it thin against the grain keeps every bite tender. Peppery arugula, juicy tomato and a touch of mustard cut through the richness of the beef, butter and mayo.
Ingredients for Steak Sandwich with Caramelized Onions
- 3/4 cup mayonnaise, preferably whole egg
- 1 large garlic clove, minced
- 3 large onions, peeled and finely sliced
- 3 tbsp unsalted butter
- 2 tbsp brown sugar
- 1 tbsp balsamic vinegar
- 1/4 tsp kosher salt and 1/4 tsp black pepper, for the onions
- 1 1/4 lb beef grilling steak, such as sirloin or ribeye
- 1/2 tsp kosher salt and 1/4 tsp black pepper, for the steak
- 1 tbsp vegetable oil
- 2 tomatoes, thickly sliced
- 2 oz arugula or other lettuce
- American style mustard, to taste
- 1 loaf Turkish bread, about 24 inches long (or 4 sandwich rolls)
Beef steak. Sirloin, rump or ribeye all work. Look for a steak about 1 inch thick that cooks evenly in a hot pan.
Onions. Yellow, white or brown onions caramelize well. Slice them evenly and thinly so they cook down at the same rate.
Garlic mayo. Whole egg mayonnaise has the richest flavor. Mince the garlic very finely so it blends in instead of leaving sharp bites.
Turkish bread. Soft, airy Turkish bread soaks up juices without falling apart. Sandwich rolls or ciabatta are good alternatives.
Tomato, arugula and mustard. Thick tomato slices add juice, arugula gives a peppery bite and a little mustard supplies tang.
How to Make Steak Sandwich with Caramelized Onions
1. Make the garlic mayo. Stir the mayonnaise and garlic together in a bowl. Cover and refrigerate for at least 30 minutes while you prepare everything else.
2. Start the onions. Melt the butter in a large skillet over medium low heat. Add the onions and stir to coat, then cover and cook for 20 minutes, stirring now and then.
3. Brown the onions. Remove the lid and cook for another 20 minutes until golden. If they are not coloring, raise the heat a little.
4. Finish the onions. Stir in the brown sugar, balsamic vinegar, salt and pepper and cook for 10 more minutes until jammy. Keep them warm.
5. Season the steak. Pat the steak dry and season both sides with the salt and pepper.
6. Sear the steak. Heat the oil in a frying pan over high heat and sear the steak for 3 to 5 minutes per side, until it reaches at least 145 degrees F.
7. Rest and slice. Let the steak rest for 5 minutes, then slice it thinly against the grain.
8. Build the sandwich. Cut the bread open and spread both sides with the garlic mayo. Layer the beef, onions, tomatoes, arugula and a little mustard.
9. Press and serve. Close the sandwich, press down gently and cut it into four portions.
How to Serve Steak Sandwich with Caramelized Onions
Serve the sandwiches warm, with a side of macaroni salad with sour cream for a cookout style meal, or a crisp Italian house salad for a lighter plate. Sheet pan sausage and potatoes make a satisfying side for a crowd, and a cold strawberry pineapple mojito completes a relaxed weekend spread.
How to Store and Reheat Steak Sandwich with Caramelized Onions
Store the components separately for the ideal results. Keep the sliced steak, onions and garlic mayo in airtight containers in the refrigerator for up to 3 days, and store the tomatoes and arugula separately. Warm the steak and onions in a skillet until hot throughout, reaching 165 degrees F, then assemble on fresh bread. An assembled sandwich turns soggy, so it is ideal when eaten right away. Freezing is not recommended.
Tips and Variations for Steak Sandwich with Caramelized Onions
Slice against the grain. Cutting across the muscle fibers shortens them and makes every bite tender.
Do not rush the onions. Low heat is what turns them sweet and jammy instead of burnt.
Make the onions ahead. They keep in the refrigerator for a few days and reheat beautifully, saving time on busy nights.
Toast the bread. A quick toast on the cut sides stops the juices from soaking in too fast.
Rest the steak. A 5 minute rest keeps the juices inside the meat rather than on the board.
Swap the greens. Baby spinach or romaine can replace arugula for a milder flavor.
Add cheese. Provolone or Swiss melted under a broiler gives extra richness.
Handle beef safely. Cook steak to at least 145 degrees F and review the general leftover guidance from University of Wisconsin Extension before storing.
Frequently Asked Questions About Steak Sandwich with Caramelized Onions
What cut of beef is ideal for a steak sandwich with caramelized onions?
Sirloin, rump and ribeye all work well. Choose a cut about 1 inch thick, and slice it thinly against the grain after resting.
Can I make a steak sandwich with caramelized onions ahead of time?
You can make the onions and garlic mayo a few days ahead. Cook and slice the steak just before serving, then assemble the sandwiches.
Why are my onions not browning in a steak sandwich with caramelized onions?
The heat is probably too low or the pan is too full. Raise the heat slightly after the lid comes off and stir more often.
Can I use leftover steak?
Yes. Slice cold steak thinly and warm it briefly in a skillet with a spoonful of onions so it does not overcook.
What bread works well?
Turkish bread is traditional here, but ciabatta, baguette and sturdy sandwich rolls all work.
Steak Sandwich with Caramelized Onions
Equipment
- large skillet with lid
- Frying pan
- Bread knife
- Small bowl
Ingredients
Main Ingredients
- ¾ cup mayonnaise whole egg preferred, for the garlic mayo
- 1 large garlic clove minced, for the garlic mayo
- 3 large onions peeled and finely sliced
- 3 tbsp unsalted butter
- 2 tbsp brown sugar
- 1 tbsp balsamic vinegar
- ¼ tsp kosher salt for the onions
- ¼ tsp black pepper for the onions
- 1 ¼ lb beef grilling steak such as sirloin or ribeye, about 1 inch thick
- ½ tsp kosher salt for the steak
- ¼ tsp black pepper for the steak
- 1 tbsp vegetable oil
- 2 tomatoes thickly sliced
- 2 oz arugula or other lettuce
- 1 tbsp American style mustard or to taste
- 1 Turkish bread loaf about 24 inches long, or 4 sandwich rolls
Instructions
Cooking
- Mayo. Mix the mayonnaise and garlic and chill for at least 30 minutes.
- Onions. Cook the onions in butter over medium low heat, covered, for 20 minutes, then uncovered for 20 more minutes until golden.
- Glaze. Stir in the sugar, vinegar, salt and pepper and cook for 10 minutes until jammy.
- Steak. Season the steak and sear it in hot oil for 3 to 5 minutes per side until at least 145 degrees F, then rest for 5 minutes and slice thinly.
- Assemble. Spread the bread with garlic mayo and layer the beef, onions, tomato, arugula and mustard.
- Serve. Press gently and cut into 4 portions.
