Preheat oven to 375°F (190°C). Separate eggs, placing whites in a large clean bowl and yolks in a medium bowl.

Beat egg yolks with cream (if using), salt, and white pepper until smooth and pale yellow.

Add cream of tartar to egg whites and whisk with electric mixer until stiff, glossy peaks form.

Gently fold 1/3 of the whipped whites into the yolk mixture to lighten it, then carefully fold this back into remaining whites until just combined.

Heat butter in a 10-inch oven-safe skillet over medium heat, swirling to coat bottom and sides.

Pour egg mixture into hot skillet, gently smoothing top. Sprinkle with cheese and cook on stovetop for 2 minutes.

Transfer skillet to oven and bake until puffed, golden, and center is just set but still jiggles slightly.