01 - Preheat oven to 350°F. Generously grease a 6-cup muffin tin with olive oil or melted butter.
02 - In a mixing bowl, vigorously whisk eggs, milk or cream, salt, and pepper until fully combined.
03 - Gently fold shredded cheese, smoked salmon, chopped onion or shallot, spinach, and dill into the egg mixture.
04 - Distribute the mixture evenly among the muffin cups, filling each about three-quarters full.
05 - Bake for 18 to 20 minutes until set and tops are lightly golden.
06 - Allow muffins to cool for 5 minutes, then run a knife around the edges to release and remove from the tin.
07 - Garnish with additional dill if desired. Serve warm or at room temperature.