Begin by thoroughly washing and drying the arugula to maintain its crispiness. While it dries, grate the Parmesan cheese until you have about ⅔ cup, and thinly slice half of a red onion into half-moons for delightful crunch. Set these ingredients aside.

In a small bowl, whisk together the lemon zest, freshly squeezed lemon juice, olive oil, honey, mild mustard, and miso paste if you’re using it. Combine these ingredients until the mixture is smooth and well-blended, creating a vibrant dressing that will enhance the flavors of your salad. Set the dressing aside while you focus on cooking the steak.

Season your 9 oz beef steak generously with ½ teaspoon of salt and ¼ teaspoon of pepper. Heat a skillet over high heat and add 0.5 tablespoons of olive oil and 2 teaspoons of butter. Once melted and sizzling, place the steak in the pan. Sear for about 3.5 minutes on each side for a medium-rare finish, basting with garlic and butter halfway through.

After cooking, remove the steak from the skillet and transfer it to a cutting board. Allow it to rest for 2 minutes; this helps retain its juices. Once rested, slice the steak thinly against the grain to ensure tenderness, ready to be beautifully arranged atop your Arugula Steak Salad.

In a large bowl, combine the freshly dried arugula, thinly sliced red onions, and half of the zesty dressing. Toss these ingredients gently to coat the arugula with the dressing. Then, sprinkle in the grated Parmesan cheese and give it another toss to distribute the flavors evenly before layering the sliced steak on top.

Drizzle the remaining dressing over the assembled salad, ensuring every bite is flavorful. Add more grated Parmesan as desired for an extra touch of creaminess. Your Arugula Steak Salad is now ready to be served, offering a delightful combination of textures and tastes in every bite.