Heat oil to medium-high heat in a large nonstick skillet. Once pan is very hot, season both sides of steak with salt and pepper. Cook for 3 to 4 minutes per side, or until steak is slightly firm to the touch. Remove to a cutting board.
Meanwhile, lower heat to medium. Add tomatoes and garlic to the pan. Cook for 2 minutes, shaking the pan occasionally. Add balsamic vinegar and cook for 2 more minutes, until tomato skins begin to split. Remove pan from the heat and season with salt and pepper.
Slice steak thinly and divide between plates, topping each portion with balsamic tomatoes.