Nothing tops low-temperature poaching with olive oil when it comes to baking steak to melt-in-your-mouth tenderness. Oil holds a consistent temperature better than water or air -- the cooking mediums used for braising and roasting -- and contributes a velvety mouthfeel you can't get from anything else. The best part about olive-oil poaching is once you heat the oil to the steak's target temperature, 130 degrees Fahrenheit for medium-rare, the steak won't cook past it, so you avoid overcooking. You need a Dutch oven's superior insulation and heat retention to oil poach steak successfully, though.
Take the steak out of the refrigerator and let it come up to room temperature. It takes about 30 minutes per pound for a chilled steak to reach room temperature. Season the steak with kosher salt and freshly ground black pepper after it warms up.
Heat the oven to 325 F. Heat a few tablespoons of olive oil in a Dutch oven over medium heat and sear the steak until golden brown on both sides.
Pour enough olive oil in the Dutch oven to cover the steak and attach a deep-fry thermometer. Don't use expensive finishing olive oil; regular extra-virgin works fine. You can use a digital instant-read thermometer if you don't have a deep-fry thermometer.
Bring the olive oil to between 125 and 130 F if you want to cook the steak to medium-rare; 135 F for medium; and 155 F for well done. Cover the Dutch oven with its lid and place it in the oven.
Poach filets, ribeye, strip, flatiron and T-bone steaks for 45 minutes. Poach tough cuts, such as sirloin, top blade, flank, skirt and round, until they cut easily with a fork, about 1 1/2 to 2 hours.
Take the Dutch oven out of the conventional oven and transfer the steak to a plate lined with paper towels. Pat the steak with a paper towel to blot up excess oil and serve as soon as possible.
You can reuse the olive oil if you strain it through a fine-mesh sieve lined with cheesecloth and store it in an airtight container in the refrigerator. You can only use the oil for poaching or sauteing, though.