Step 1

In a medium nonstick skillet, heat butter over medium heat until starting to foam. Add onion and cook, stirring, until translucent, about 5 minutes. Add eggs and cook, stirring constantly, until loosely curds form throughout. Add feta and mozzarella and cook, stirring, until mozzarella is melted and eggs are softly scrambled, about 1 minute. Stir in dill and remove from heat. Season lightly with salt and pepper.

Step 2

Arrange biscuit bottom halves on plates and spoon eggs on top. Close biscuits with top halves and serve immediately.