01 -
Preheat oven to 350°F and generously grease a 2-quart casserole dish with butter.
02 -
In a medium heavy saucepan over medium heat, warm the milk and buttermilk until steaming, without boiling.
03 -
Gradually pour in cornmeal, whisking constantly to avoid lumps. Stir frequently until mixture thickens, 10–12 minutes.
04 -
Remove from heat and stir in butter, thyme, salt, and pepper until fully combined. Let mixture rest for 10 minutes.
05 -
In a bowl, combine egg yolks with 2 cups of the warm cornmeal mixture. Stir back into the saucepan mixture until uniform.
06 -
Beat egg whites to stiff peaks. Gently fold into the cornmeal base until no streaks remain and batter is smooth.
07 -
Transfer batter to prepared dish. Bake for 35–40 minutes until puffed, lightly browned, and set. Serve hot or warm.