01 - Preheat oven to 350°F. Generously grease a 6-cup muffin tin with olive oil or melted butter.
02 - Whisk eggs, milk or cream, salt, and pepper in a mixing bowl until fully combined.
03 - Stir in shredded cheese, chopped smoked salmon, diced red onion or shallot, chopped baby spinach, and dill.
04 - Divide mixture evenly among the greased muffin cups, filling each about three-quarters full.
05 - Bake for 18 to 20 minutes, or until set and lightly golden on top.
06 - Cool for 5 minutes, then run a knife around the edges to loosen. Gently remove muffins from the tin.
07 - Garnish with additional fresh dill if desired. Serve warm or at room temperature.