Cook potatoes, covered with vented plastic wrap, in a microwave-safe bowl for 5 minutes, stirring once.
Meanwhile, season steaks with salt and pepper. Heat a 12-inch skillet over medium-high heat; add 1 teaspoon of the oil. Add steaks; cook 3 to 4 minutes per side. Transfer to a platter; cover to keep warm. For sauce, in the same skillet cook tomatoes and garlic in 1 teaspoon of the oil until softened. Stir in olives and oregano; cook for 3 minutes more.
In a separate nonstick skillet cook potatoes in 2 teaspoons hot oil over medium-high heat for 4 minutes. Season to taste with salt and pepper. Serve steaks and potatoes with sauce.