Savory Dutch Baby

From Kinfood.
Ingredients:
90 grams (3/4 cup) flour
3/4 teaspoon kosher salt
3 eggs, ideally at room temperature
1 teaspoon vanilla extract (omit if making savory)
175 grams (1 cup) milk, ideally at room temperature
3 tablespoons unsalted butter
Smoked trout
Sour cream
Shallots
Dill

In a large bowl, whisk together the flour and salt.
In a separate bowl, whisk together the eggs, vanilla, and milk until smooth.
Add the wet ingredients to the dry ingredients and whisk just until smooth with no lumps.
Preheat your oven to 425? F, add the butter in a 10” cast iron skillet, and set in the oven while it preheats.
Check the butter a few times, and remove from the oven when the oven has come to temperature and butter is melted.
Immediately add the batter, return to the oven, and bake for 20-25 minutes.
Remove from the oven and let rest for about 5 minutes before serving with smoked trout, sour cream, shallots, and dill.