In a medium-sized mixing bowl, whisk together everything except the egg, stirring until fairly smooth; a few small lumps can remain., Tent the bowl lightly with plastic, and allow it to rest at room temperature for 3 hours; it'll start to bubble just a bit., Refrigerate the batter overnight., Just before cooking the pancakes, stir in the beaten egg., Heat a 9" or 10" skillet over medium heat; or heat a 9" or 10" electric skillet to 300°F; or heat a griddle that's at least 9" to 10" wide, and easy to pick up and handle., Place 1 teaspoon vegetable oil and 1 teaspoon butter into the skillet, swirling them around until the butter melts. Yes, use 1 teaspoon each; this is what will give the pancakes their signature crisp edges., Pour a scant 1/2 cup batter into the pan, tilting the pan until the batter forms a circle about 9" in diameter. It's important that you do this quickly, before the pancake has a chance to set; the thin edges that result from tilting the pan to distribute the batter become wonderfully crispy., Cook the pancake for about 2 to 2 1/2 minutes, or until its underside is golden brown. Flip it over, and cook about 1 1/2 to 2 minutes more, until golden., Transfer to a plate (or lightly greased baking sheet, if you want to keep the pancake warm in the oven while you cook the remainder). Repeat with the remaining batter., Serve the pancakes with butter and syrup. Or spread sour cream (or whipped cream, or yogurt), layer strawberries down the center, and roll like a blintz.