Place the flour, cream, eggs, 2 tbsp melted butter, and salt in a blender or food processor fitted with the blade attachment. Blend for 10 seconds, scrape down the sides, and then blend for another 20 seconds. The batter will be quite loose and liquidy.
Leave the batter in the blender and set aside to rest 20 to 25 minutes. This gives the flour time to absorb the liquid.
Meanwhile, place a 9" or 10" cast iron skillet on the middle rack to warm along with the oven. Heat the oven to 425°F.
In a small bowl, combine the parmesan thyme, chives, and basil.
When ready to make the pancake, remove the skillet from the oven using oven mitts and place it on top of the stove. Add the remaining 2 tbsp butter and swirl the pan to melt the butter and coat the bottom and sides of the pan.
Pour the batter on top of the butter. Tilt the pan if needed so that the batter runs evenly to all sides. Place the skillet in the oven. Working quickly, sprinkle the cheese/herb mix gently overtop of the batter.