Preheat the broiler. Combine the chile powder, sugar and1 teaspoon each salt and pepper in a small bowl. Brush the steak all over with 1 tablespoon olive oil, then rub the spice blend on both sides. Transfer to a broiler pan; let sit 10 minutes.
Meanwhile, heat the remaining 1 tablespoon olive oil in a medium saucepan over medium-high heat. Add the onion and peppers and cook, stirring occasionally, until the onion is translucent, about 4 minutes. Add the frozen corn; cook, stirring, 2 minutes. Reduce the heat to medium and add the evaporated milk. Cook until thick and creamy, about 7 minutes. Season with salt and pepper.
Broil the steak 3 to 4 minutes per side for medium rare. Transfer to a cutting board and let sit 5 to 10 minutes, then slice against the grain. Serve the steak with the creamed corn; sprinkle with the scallions and serve with lime wedges.