In a mixing bowl, crack the eggs, then add the milk or cream, salt, and pepper. Use a whisk or fork to beat the mixture until combined and slightly frothy.
Place the non-stick skillet on medium-low heat and add the butter. Allow the butter to melt and foam, but do not let it brown.
Pour the beaten egg mixture into the skillet and let it sit for a few seconds until it begins to set around the edges.
Using the spatula, gently stir the eggs, pushing them from the edges towards the center of the skillet. Continue to cook and stir until the eggs are mostly set but still slightly runny, about 2 to 3 minutes.
Remove the skillet from the heat, as the eggs will continue cooking off the heat. If you've chosen to add any optional ingredients, fold them in now.
Serve the scrambled eggs immediately while they’re still warm, garnished if desired.