Copycat Panera Bread Steak & White Cheddar Panini

Panera Bread’s Steak and White Cheddar Panini keeps people coming back because the pickled red onions set it apart from every other steak sandwich on the menu. This copycat layers roast beef, white cheddar, and horseradish sauce on ciabatta, then tops it with quick-pickled red onions and presses everything until the cheese melts and the bread is toasted. The pickled onions take about 30 minutes to prepare and carry the bright, tangy flavor that makes this sandwich taste like the Panera original. Prep the onions ahead of time, and the rest of the sandwich comes together in minutes.

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Panera Bread’s Steak and White Cheddar Panini has a straightforward lineup of ingredients, but the pickled red onions are what make it distinctive. Without them, you have a solid steak-and-cheese sandwich. With them, the whole thing comes together as something closer to a restaurant-quality meal you can make at home for a fraction of the price.

The sandwich uses ciabatta as the bread base, which holds up well to pressing without becoming soggy. Horseradish sauce on the top half adds a subtle heat that plays well against the mild creaminess of the white cheddar. Everything pressed together in a panini press gives you the melted cheese and golden crust that defines the original.

Ingredients

For the Pickled Red Onions:

• Red onion – Provides the base for the pickled topping that gives this sandwich its signature tangy bite.
• White vinegar – Creates the acidic brine that pickles the onions and gives them their brightness.
• Sugar – Balances the acidity of the vinegar and softens the sharpness of the raw onion.
• Salt – Draws moisture from the onion and seasons the brine.
• Water – Dilutes the vinegar to the right strength for a quick pickle.

For the Sandwich:

• Cooking spray – Prevents the sandwich from sticking to the panini press plates.
• Ciabatta bread – Provides a sturdy, open-crumb base that crisps evenly under a panini press.
• Horseradish sauce – Adds mild heat and a sharp, creamy counterpoint to the beef and cheese.
• Sliced roast beef – Provides the savory, hearty protein layer at the center of the sandwich.
• White cheddar cheese – Melts smoothly and adds a sharp, tangy richness that pairs well with the horseradish and onions.

How to Make Panera Steak and White Cheddar Panini

1. Slice onions as thin as possible.
2. Place the onions in a glass jar.
3. In a small bowl, combine white vinegar, sugar, salt, and warm water. Stir until dissolved.
4. Pour liquid into the jar with onions. Allow onions to pickle for at least 30 minutes.
5. Cut the ciabatta loaf in half horizontally.
6. Spread the horseradish sauce onto the inside of the top half.
7. Place roast beef on the bottom half.
8. Place pickled onions and cheese on top of the roast beef.
9. Place the top half on the sandwich.
10. Lightly coat the inside of a panini press with cooking spray and heat the press.
11. Place the sandwich in the press and cook until the sandwich is heated through and the cheese has melted, about 3 to 5 minutes.

If you do not have a panini press, you can use a grill pan and a heavy object to press the sandwich into the pan.

How to Make Pickled Red Onions

Pickled red onions take almost 2 minutes to make, and they can be used in oh-so-many ways. You can enjoy these as a side with grilled meats, on sandwiches, or even in place of pickles.

I like to slice my onions on a mandolin, but you can use a knife to slice a red onion super thin. Then you will need some vinegar, water, and spices.

You literally combine all of these and let them rest for about 15 minutes before serving. They taste better with age, so you may even want to keep these on hand all of the time.

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Storage and Reheating Instructions

• Refrigerator Storage: The assembled sandwich is best eaten immediately after pressing. If you have leftovers, wrap them tightly and refrigerate for up to 1 day. Note that the bread will soften and lose its crust overnight. The pickled red onions can be stored separately in a sealed jar in the refrigerator for up to 2 weeks.
• Reheating Method: Reheat a leftover sandwich in a panini press or a dry grill pan over medium heat for 2 to 3 minutes per side until warmed through and the bread has crisped again. Avoid microwaving, which will make the ciabatta soft and chewy.
• Freezer Storage: Not recommended for the assembled sandwich. The pickled onions do not freeze well, and the bread texture deteriorates significantly after freezing. Prepare fresh when possible.

Can’t get enough of Panera Bread? Try these copycat recipes!

• Panera Apple Crunch Muffin
• Panera Autumn Squash Soup
• Panera Baja Bowl
• Panera Black Bean Soup
• Panera Broccoli Cheddar Soup
• Panera Chipotle Chicken Avocado Melt
• Panera Frontega Chicken Sandwich
• Panera Mac and Cheese Recipe

Favorite Sandwich Recipes

• Air Fryer Grilled Cheese
• Chick Fil A Sandwich
• Chicken Fried Steak Sandwich
• Ham Salad Sandwich
• Homemade Sloppy Joes
• Honey BBQ Chicken Sandwich
• Monte Cristo Sandwich

Check out more of my easy sandwich recipes and the best Panera Bread recipes here on CopyKat!