Place a 6-cup popover can in the bottom third of an oven. Place a baking sheet on the rack underneath to catch any drips. Preheat the oven to 400 degrees.
Sift together the flour and salt through a fine mesh sieve. Set aside.
In a large mixing bowl, whisk the eggs until frothy, about 2 minutes.
Pour the milk into a small saucepan and heat on medium-high until the milk just starts to bubble. Remove from the heat and slowly drizzle the milk into the beaten eggs, whisking constantly to prevent the eggs from cooking. Keep slowly adding the milk until it is all incorporated into the eggs. Gradually whisk in the flour mixture just until blended.
Remove the popover pan from the oven (it should have preheated at least 15 minutes) and spray the cups with a nonstick vegetable spray. Divide the batter between the 6 cups filling them about three-fourths full. Sprinkle each cup of batter with 1/6th of the grated cheese.
Immediately return the pan to the oven and bake for 15 minutes. Quickly open the oven and rotate the pan 180 degrees, then reduce the oven to 350 degrees. Continue baking the popoversuntil puffed and browned, about 35 minutes. Do not open the oven again after rotating the pan.
Remove the popovers from the pan and serve immediately.