Softened unsalted butter or nonstick cooking spray, for greasing baking vessel(s)
2 tablespoons fine cornmeal, plus more for dusting ramekins
5 whites plus 3 yolks from 5 large eggs, separated
One pot cooked grits (about 1 pound; 450g cooked grits), slightly cooled but still warm and smooth
3/4 cup grated mild or medium cheddar cheese (2 1/4 ounces; 65g)
1 tablespoon finely sliced chives
Set oven rack to middle position and preheat to 350°F. Grease four 12-ounce ramekins (or, alternatively, one 8- by 8-inch baking dish) generously with butter or cooking spray, making sure to cover bottoms and sides all the way up to the rims. Dust with an even coating of cornmeal, making sure to cover bottoms and sides all the way up to the rims; tap out excess cornmeal.
In a stand mixer fitted with the whisk attachment (or in a medium bowl and using a hand mixer), beat egg whites at low speed until foamy, then increase speed to high and beat until stiff peaks form. Set aside.
Fold the 2 tablespoons cornmeal into the grits along with the cheese, chives, and salt until well combined. Add egg yolks 1 at a time, stirring until each is fully incorporated before adding next.
Working in 3 additions, carefully fold beaten egg whites into the grits mixture just until well combined. The resulting mixture should be light and airy, not heavy or thin.
Fill prepared ramekins 3/4 of the way full with the grits mixture. Set ramekins on a rimmed baking sheet. Bake on middle rack until soufflés have risen and are just starting to brown on top, about 30 minutes. Remove carefully and serve immediately. The soufflés should remain risen for about 10 minutes after removing from the oven, and are just as good after they fall.