Preheat oven to 375 degrees. Use the 2 teaspoons of butter to grease six 6-ounce ramekins. Dust the insides of the ramekins with the parmesan cheese, wiping away any excess from around the rim.
In a small saucepan over a medium heat, melt the remaining 5 tablespoons butter. Add the rice flour and cook, stirring constantly, 2 to 3 minutes.
Add the milk and whisk until thick and incorporated, about 5 minutes. Add the cheddar cheese, egg yolks, thyme, salt and nutmeg, stirring until the cheese is melted. Remove from the heat and set aside.
Use a mixer with the whisk attachment, whip the egg whites until they form stiff peaks, about 3 minutes. Using a rubber spatula, carefully fold the egg whites into the cheese and milk mixture until just incorporated.
Spoon the mixture into the prepared ramekins, leaving 1/4 inch space at the top. Bake 25 to 30 minutes, or until golden brown. (When you open the oven to check the souffles, be gentle so as not to shake them.).