Line a large bowl with paper towels. Heat vegetable oil over medium heat to 375°F in a large sauté pan
or dutch oven
. Add 1/3 of the beef slices and fry until the batter starts to darken, about 3 minutes. Use a spider or slotted spoon to remove the beef from the pan and place it in the paper towel-lined bowl. Let oil climb back up to 375°F, and repeat the above process twice more.