This is by far the juiciest Steak Sandwich I’ve ever made. This is Chimichurri Steak Sandwich that brings together perfectly seared steak with vibrant, herbaceous chimichurri and creamy mustard aioli. It’s a flavour-packed sandwich that elevates the classic steak sandwich to restaurant quality!

Understanding Your Components

1. Steak: I recommend using ribeye, sirloin, or strip steak for this recipe. These cuts have great marbling and flavour that work beautifully in sandwiches. Aim for steaks that are about 1 to 2 inch thick. Let your steak come to room temperature for about 30 minutes before cooking for the best results. Even better, dry age your steak overnight by sprinkling a bit of salt onto your steak and leave it uncovered in the fridge over night to draw out moisture.
2. Cooking Method: A cast iron skillet or grill pan works perfectly for getting a beautiful sear on your steak. High heat is key to developing that perfect crust while keeping the interior tender and juicy. Don’t move the steak too much while cooking – let it develop that gorgeous caramelization.
3. Chimichurri: This vibrant Argentinian sauce made with fresh herbs, garlic, vinegar, and olive oil is the perfect complement to steak. The acidity cuts through the richness of the meat while the herbs add freshness. Traditional chimichurri uses parsley and oregano, but feel free to add cilantro for extra brightness. Make it at least 30 minutes ahead to let the flavors meld together.
4. Mustard Aioli: A creamy, tangy sauce that bridges the gap between the bold chimichurri and rich steak. The Dijon mustard adds a sophisticated sharpness that pairs beautifully with beef. Whole grain mustard can be substituted for extra texture.
5. Lettuce: Arugula is my top choice here – its peppery bite complements the steak perfectly and adds a nice contrast to the rich sauces. If you prefer something milder, butter lettuce or romaine work well too.
6. Bread: A crusty baguette or ciabatta roll is ideal. You want something sturdy enough to hold all the delicious components without falling apart, but with good flavour to complement the steak.

Tips!

Steak Temperature: Use an instant-read thermometer for perfect doneness every time. For medium-rare (recommended), aim for 130-135°F internal temperature.

Resting: Always let your steak rest for 5-10 minutes after cooking. This allows the juices to redistribute throughout the meat, ensuring every bite is juicy.

Slicing: Slice your steak against the grain for maximum tenderness.

Storage and Reheating Guide

• Mustard aioli can be stored in the fridge for up to 5 days
• Chimichurri stays fresh in the fridge for up to 1 week
• Cooked steak can be stored in the fridge for up to 3 days.
• Reheat gently to avoid overcooking
• Store each component separately.
• Assemble fresh and serve immediately

Make ahead tips:

• Make chimichurri the day before – it actually tastes better after the flavours have time to meld
• Prepare mustard aioli up to 2 days in advance
• Season steaks and bring to room temperature 30 minutes before cooking
• Wash and prep lettuce ahead of time
• Cook steaks and assemble sandwiches fresh when ready to serve

Ingredients

(makes 2 sandwiches)

1 baguette loaf
400g steak
Arugula/ Rocket
Cheese (I used cheddar)

Chimichurri:
1 cup fresh parsley, finely chopped
1 shallot, finely chopped
1/4 cup fresh oregano, chopped (or 2 tbsp dried)
3 garlic cloves, minced
1/4 cup red wine vinegar
1/3 cup extra virgin olive oil
1/2 tsp red pepper flakes
Salt and pepper to taste

Garlic Aioli:
1 egg yolk
1 garlic clove, minced
1/4 lemon, juiced
1/2 cup vegetable oil
2 tbsp wholegrain mustard, adjust to taste
Salt

Method

1. Bread: Cut your baguette into 15cm/6inch loaves then slice in half, lengthwise.
2. Mustard Aioli: In a bowl, add in the egg yolk, garlic, lemon juice and salt. Whisk to combine and slowly drizzle in the oil while whisking continuously, it should turn into a paste/sauce. Add in the mustard and season to taste.
3. Chimichurri: in a bowl, combine all the ingredients together and set aside.
4. Steak: Season both sides of your steak. Bring a pan with oil to a high heat and carefully place in your steak. Depending on the thickness of your steak, cooking time will vary. My steak was 2 inches thick and I did a total of 7 minutes, flipping halfway. Set aside and let it rest for at least 3-4 minutes then slice your steak.
5. Assemble: Toast your bread slices (optional). On the bottom piece, spread a generous layer of the mustard aioli, then top with steak slices and cheese. Blow torch or place the open sandwich under the broiler to melt the cheese. Top with Chimichurri, arugula/rocket and the second piece of bread. Enjoy!