New Zealand Grass-fed Wagyu Steak with Creamy French Onion Mushrooms

This post may contain affiliate links.

Learn how to cook the perfect New Zealand grass-fed wagyu steak in a cast iron skillet! Serve the steak with this recipe for Creamy French Onion Mushrooms and you’ve got one seriously delicious dinner!

Overhead shot of sliced wagyu steak on wood cutting board with rosemary sprigs on the side

Today’s post is sponsored by Beef + Lamb New Zealand and First Light.

Today’s recipe is not just any recipe, it’s a recipe made to impress! New Zealand 100% grass-fed Wagyu from First Light has outstanding marbling, creating a tender, delicious steak! The flavor profile is unique with the sweet, nutty notes that Wagyu is famous for and an extra depth of flavor from being raised on grass.

New Zealand cattle is grass-fed year-round. The cattle are raised humanely without antibiotics or hormones and are allowed to roam and graze freely. This healthy, low-stress lifestyle for the animals translates into a healthy, tender steak.

When it comes to cooking grass-fed Wagyu, it couldn’t be easier! Because of the beautiful marbling and fat content in the Wagyu, there’s no need to cook the steak in butter or oil. All you need is a sprinkling of fresh cracked black pepper and sea salt to make this a seriously delicious steak dish.

Grass-fed Wagyu steaks can be cooked on the grill or on the stove in a cast iron skillet. All it needs is a quick sear on high heat, then to finish over medium heat until you reach your preferred temperature.

Mushrooms pair amazingly well with grass-fed Wagyu steaks. In this recipe, I paired a First Light Grass-fed Wagyu New York Strip Steak with Creamy French Onion Mushrooms. They really are a match made in heaven! Creamy, earthy, mushrooms, paired with nutty, grass-fed Wagyu from New Zealand, it really doesn’t get any better than that!

Overhead shot of sliced wagyu steak in cast iron skillet with creamy mushrooms and rosemary sprigs

What is the best way to cook Grass-fed Wagyu Steak?

Searing grass-fed Wagyu steaks in a cast iron skillet on the stove is the best and easiest way to cook them.

Grass-fed Wagyu Steak Cooking Tips

  • Always make sure to allow the steak to come to room temperature before cooking. Removing the Wagyu steaks from the refrigerator 60 minutes prior to cooking will allow them to come to room temperature. This allows the steak to cook more evenly and faster.
  • Season the steaks with salt and pepper. Grass-fed Wagyu is so flavorful, it does not need any more seasoning than simply salt and pepper. I do recommend a coarse sea salt and fresh cracked black pepper to get a nice crust on the steak.
  • Preheat a cast iron skillet over high heat. To achieve a delicious crust on the steak, you want to make sure your skillet is nice and hot before adding the steak. The steak should be seared for 2 minutes per side. Reduce the heat to medium-high and finish the steaks for an additional 3 minutes per side or until the internal temperature reaches your desired doneness.
    • 125°F for a rare steak
    • 130°F for a medium rare steak
    • 140°F for a medium steak
    • 150°F for a medium well steak
    • 160°F for a well-done steak
  • Allow the steak to rest. Just like most meats, you want to give it time to rest before slicing into it. Resting the meat will allow the juices to redistribute throughout the meat. This results in a more tender, juicy steak. After removing the steak from the skillet, loosely wrap it in foil and allow it to rest for 5-10 minutes.

What do you serve with Grass-fed Wagyu Steak?

New Zealand grass-fed wagyu steak, from First Light, pairs perfectly with mushrooms and greens. Peppery arugula is a great pairing for the nutty Wagyu. This Arugula Blue Cheese Pesto is a great addition to this grass-fed Wagyu steak recipe. Chimichurri Sauce is also a wonderful pairing with grass-fed Wagyu.

My favorite way to serve New Zealand grass-fed Wagyu is with Creamy French Onion Mushrooms!

How to make Creamy French Onion Mushrooms

Melt butter in a large skillet over medium high heat. Add thinly sliced onions and sauté for 5 minutes. Add sliced baby bella or cremini mushrooms, garlic and French Onion Dip Mix. Sauté on the stove for an additional 5-6 minutes.

Sprinkle cornstarch over the mushrooms, then add beef broth to the skillet. Simmer for 1-2 minutes, then reduce the heat to low. Add half-and-half and simmer for an additional 6 minutes. Stir in freshly grated parmesan cheese and serve.

These mushrooms are so delicious, I could eat them straight with a spoon, but they’re even better when served alongside a delicious seared grass-fed Wagyu steak!

Sliced wagyu steak on wood cutting board with fresh rosemary sprigs

Want to learn more about 100% grass-fed Wagyu from New Zealand? Visit the websites for Beef + Lamb New Zealand and First Light for more information, cooking tips and recipes!

Sliced wagyu strip steak on wood tray with rosemary sprigs and black peppercorns
5 from 3 votes
Print

New Zealand Grass-fed Wagyu New York Strip Steak with Creamy French Onion Mushrooms

Learn how to cook the perfect New Zealand grass-fed Wagyu steak in a cast iron skillet! Serve the steak with Creamy French Onion Mushrooms on the side for one delicious dinner!

Course Main Course
Cuisine American
Prep Time 35 minutes
Total Time 35 minutes
Servings 2 people
Calories 1117 kcal
Author Whitney Bond

Ingredients

Wagyu Steak

  • 2 New Zealand Grass-Fed Wagyu New York Strip Steaks from First Light approx. 12 oz each
  • 1 tsp coarse sea salt
  • 1 tsp fresh cracked black pepper

Creamy French Onion Mushrooms

  • 2 tbsp butter
  • 1 cup onions thinly sliced
  • 16 oz baby bella mushrooms sliced
  • 3 cloves garlic minced
  • 1 tbsp French onion dip mix
  • 2 tbsp cornstarch
  • ½ cup beef broth
  • ½ cup half-and-half
  • ¼ cup parmesan cheese grated

Instructions

Grass-fed Wagyu Steak

  1. Remove the steaks from the refrigerator and allow them to come to room temperature for 60 minutes.
  2. Season all sides of the steaks with coarse sea salt and fresh cracked black pepper.
  3. Heat a cast iron skillet on the stove over high heat.
  4. Once the skillet is hot, add the steaks and sear for 2 minutes per side.
  5. Reduce the heat to medium high and continue cooking the steaks for 3 minutes per side, or until the internal temperature of the steak reaches your desired doneness. (Refer to the notes below for cooking temperatures.)
  6. Remove the steak from the skillet and wrap in foil.
  7. Allow to rest for 5-10 minutes before slicing.
  8. Slice and serve immediately.

Creamy French Onion Mushrooms

  1. Add the butter to a large skillet over medium high heat.
  2. Once the butter is melted, add the onions, sauté for 5 minutes.

  3. Add the mushrooms, garlic and French onion dip mix, sauté for 6 minutes.

  4. Sprinkle the cornstarch over the mushrooms, then add the beef broth and simmer for 1-2 minutes.
  5. Reduce the heat to medium-low and add the half and half, cook for 6 minutes.
  6. Stir in the parmesan cheese and serve.

Recipe Video

Recipe Notes

  • I recommend preparing the mushrooms while the steaks are coming up to room temperature. The mushrooms can then simmer on the side while you sear the grass-fed Wagyu.
  • Temperature guide for cooking grass-fed Wagyu Steaks.
    • A temperature of 125°F will result in a rare steak.
    • A temperature of 130°F will result in a medium rare steak.
    • A temperature of 140°F will result in a medium steak.
    • A temperature of 150°F will result in a medium well steak.
    • A temperature of 160°F will result in a well-done steak.
  • The calories listed in the recipe card are per serving.