Drain corn and pat dry with paper towels. Heat a drizzle of oil in a large, oven-safe pan over high heat. Add corn and cook, stirring occasionally, until slightly charred, 4-5 minutes. (TIP: If corn begins to pop, cover pan.) Reduce heat to medium and add tomato, scallion whites, and Southwest Spice. Cook, stirring occasionally, until tomato breaks down, about 2 minutes. Season with salt and pepper.