How to Make It
In a small skillet, heat 1 teaspoon of the olive oil. Add the garlic and cook over low heat until fragrant but not browned, about 1 1/2 minutes. Stir in the butter until melted, then add the sake and mirin. Season with salt and pepper; remove from the heat.
In a large skillet, heat the remaining 2 tablespoons of olive oil. Season the steaks with salt and pepper and cook over moderate heat until browned outside and rare within, 7 minutes per side. Transfer to plates, drizzle with the sake-mirin butter and serve.