Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to make flank steak pinwheels [title] Preheat the grill pan. [step] To ensure that the grill pan is hot enough to cook the steak, it's important to preheat it. Place the pan on the stovetop, and turn the heat to high.

Ending1: Allow the pan to heat for about 10 minutes. [substeps] If you use a gas grill, turn the heat to medium-high and allow the pan to heat until it is hot to the touch. Ending2: Once the pan is hot, take out a stack of skewers, and place them in the center of the pan to allow them to rise. [substeps] The skewers should be approximately 1/3 of the way up the pan so they cook evenly. Ending3: Allow the grill to heat for about 30 minutes. [substeps] If you're not sure how long to allow the grill to heat, it's very important to gauge the temperature. Ending4: Allow the pan to heat for approximately 5 minutes. [substeps] You'll know that the pan is hot enough when you sprinkle a few drops of water over the pan and it evaporates quickly.

Answer format: ending1/ending2/ending3/ending4