Wagyu Steak Sandwich with Bone Marrow Mayo Recipe

Wagyu Steak Sandwich with Bone Marrow Mayo Recipe

By Nicholas Fiorentino

Drawing inspiration from Ecuador, this Wagyu Steak Sandwich with Bone Marrow Mayo Recipe takes a simple sandwich and elevates it by using high-quality ingredients. Pulling flavors from Ecuador to enhance the Wagyu Tasajo steaks, generously provided by The Meatery, this easy-to-make, open-faced sandwich makes a fantastic grilled appetizer. Perfect for impressing guests or putting out on your next game day. Add a succulent handmade mayo and green chili drizzle, you are not only doing justice to the steak but providing tantalizing flavors that you won’t taste anywhere else.


Ecuadorian Tasajo Steak Sandwiches:

  • 2x 16 oz. (0.5 kg) Australian Wagyu Tasajo steaks or flap steak
  • 1 tsp. (14 g) cumin
  • 1 tsp. (3 g) salt
  • 1 tsp. (1.5 g) garlic powder
  • ½ tsp. (2 g) freshly ground pepper
  • Leafy greens of preference
  • 1 crusty baguette, sliced
  • Oil or butter

*Pour any rendered marrow fat liquid into the measuring cup and fill the rest of the way with the neutral oil to reach 1½ cups.


Bone Marrow Mayo:

  • 2 split marrow bones 
  • 3 egg yolks
  • ½ lemon, juiced
  • 1 tbsp. (15 ml) Dijon mustard
  • *1½ cups (355 ml) neutral oil like canola or light olive or avocado
  • Seasoning to taste


Green chili sauce:

  • 3 jalapeno peppers, chopped
  • 1½ cups (16 g) cilantro leaves
  • 1 lime zested and juiced
  • 1 clove garlic, chopped
  • 1 tsp. (3 g) kosher salt 
  • 1 tsp. (5 g) sugar



  1. Preheat your barbecue to 350°F (177°C). Place the marrow bones, cut side up, onto a baking tray and roast for 20 minutes. Remove from the heat and allow the marrow to cool. 
  2. Once cool, scrape the bone marrow from the bones into a bowl or, better yet, a tall container that is wide enough to fit an immersion blender. Add any rendered fat from the bones into the vessel you will be measuring the oil into. Fill the remaining volume of the measuring cup with a neutral oil, like canola. 
  3. In the vessel with the marrow, add the egg yolks, lemon juice and Dijon mustard. Use an immersion blender to combine the ingredients well, then slowly start streaming in the oil until emulsified (thickened). Store in the fridge until ready to use. This can also be done with a whisk and some elbow grease or by using a blender.
  4. For the green chili sauce, combine the jalapeno, cilantro, lime zest and juice, garlic, salt and sugar in a blender and blitz until you’ve reached your desired texture. 
  5. Preheat your infrared sear station to high and the main grids on your grill to 300°F (148°C). If you don’t have a sear station, preheat two side by side burners to high, leaving the other one(s) off for a cool zone. 
  6. Season the steak thoroughly with cumin, salt, garlic powder, and pepper. Sear the Tasajo steaks on both sides until grill marks form, about 2 minutes each side, turning 90 degrees after the first minute for hatch marks. Once seared, move the steak to the cool zone on the barbecue to finish cooking to the desired temperature of no more than 130°F (54°C). Remove from the heat and rest. 
  7. While the steak is finishing or resting, slice and butter or oil the baguette slices and grill until crispy. 
  8. Slice the steak thinly and assemble the sandwiches. Top the toasted bread with a dollop of mayonnaise, a few leafy greens and a slice or three of steak. Once all assembled, drizzle everything with a little of your chili sauce and serve.


While not the traditional sandwich recipe these Wagyu Steak Sandwiches with Bone Marrow Mayo are delightful and super gourmet. Perfect for any event where you want to impress. What do you serve when you need to be #Extra?  Share your easiest, over-the-top BBQ recipes, stories and photos on our social pages like Facebook and Tiktok, using the hashtags #TheMeatery #NapoleonEats and #NapoleonGrills.

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