Cut steak into bite-size cubes. Season generously with sea salt, black pepper and paprika. Toss with kewpie mayo until fully coated right before cooking.
Heat pan over high heat. Add in mayo-coated steak cubes and allow the sides to sear until golden brown, roughly 2 minutes on each side. Transfer to plate and set aside.
In the same pan, along with any remaining juices, melt butter and add in both garlic and red pepper flakes. Saute for 1-2 minutes until fragrant and starting to crisp up.
Return the steak cubes into the pan. Stir-fry for a minute until combined.
Add in coriander leaves. Toss to combine and cook for another 30 seconds. Serve immediately.
Notes
The use of mayo helps in searing the steak and attaining a golden crust over the meat.
Kewpie mayo is preferred but regular mayo would work just fine either.
Make sure the pan/skillet is really hot before adding the steak to attain a perfect sear. This also helps to prevent overcooking the meat.
Add more chilli flakes if you desire the dish to come out spicier.
Serving ideas include a side of steamed rice and roasted vegetables, creamy mash, or toss it into your favourite pasta!