Reduce the heat to medium. Add the onion to the skillet and cook, stirring occasionally, until softened, about 3 minutes. Add the garlic and cook until fragrant, about 30 seconds. Add 1 cup long-grain white rice, 2 teaspoons dried Italian seasoning, 1/4 teaspoon red pepper flakes if using, and the remaining 3/4 teaspoon kosher salt. Stir to combine and cook until toasted, about 2 minutes.
