1. Place a medium cast iron skillet in center of oven and preheat oven to 450°. Let skillet heat at least 25 minutes total (prepare your toppings while you wait).
2. When skillet is hot, blend eggs in a blender on high speed until very frothy, about 1 minute. With motor running, gradually stream in milk, then 2 Tbsp. butter; blend another 30 seconds. Add flour, cornstarch, salt, and pepper and blend just to combine.
3. Carefully remove skillet from oven and swirl remaining 1 Tbsp. butter in skillet to coat. Immediately pour batter into skillet (butter will brown quickly, so have batter at the ready to prevent burning).
4. Bake pancake until puffed and brown around edges, 20–25 minutes. It will begin to deflate as soon as it comes out.
5. Top as desired. This needs very flavorful toppings, and preferably a moist element.
Fried eggs, avocado, and shaved ham
Smoked salmon, crème fraîche, and sliced spring onions
Sautéed kale, crispy bacon, and aged cheddar