Step 1 Preheat the oven to low, 135 °C/ 275 °F (fan assisted), or 155 °C/ 310 °F (conventional). Crack the eggs and separate the egg whites from the egg yolks. Place the egg whites into a large clean bowl or a mixer.
Step 2 Start beating the egg whites on medium-low speed. Continue for about 2 minutes until the whites become foamy. Then, add the cream of tartar (or apple cider vinegar).