Put the potatoes in a large nonstick skillet; cover with water and season with salt. Bring to a boil, reduce the heat to a simmer and cook until just tender, about 10 minutes. Drain, blot dry with paper towels and wipe out the skillet.
Meanwhile, combine the butter, grated garlic, parsley, oregano, lemon zest and a big pinch of salt in a food processor. Pulse until smooth; set aside.
Season the steak with salt and pepper. Heat a large skillet over medium-high heat. Add 2 tablespoons vegetable oil. Add the steak and cook until well browned, 3 to 4 minutes per side for medium rare. Transfer to a cutting board to rest.
While the steak cooks, heat the reserved nonstick skillet over high heat. Add the remaining 2 tablespoons vegetable oil and the potatoes. Cook, stirring occasionally, until the potatoes are browned around the edges, about 5 minutes. Add the corn, minced garlic and a pinch of salt; cook, undisturbed, until the corn is lightly browned, about 3 minutes. Add the scallions and cook, tossing, until combined. Season with salt and pepper and stir in the lemon juice.
Divide the vegetables among plates. Slice the steak and add to the plates; top with the garlic butter.