Preheat the oven to 375°F. Place a baking sheet in the oven (you'll bake the ramekins on it).
Grease ramekins generously with butter or nonstick spray. For bonus texture and easy release, sprinkle with a bit of finely grated parmesan and tap out excess.
Separate your eggs then in a large bowl, whisk the egg yolks with milk, salt, and pepper. Stir in cheese and any optional cooked veggies and/or cooked meat.
In a clean, dry bowl, beat the egg whites using an electric mixer (or whisk by hand if you're ambitious!) until soft peaks form - meaning they hold their shape but the tips flop over.
Gently fold the whipped egg whites into the yolk mixture in two additions. Use a rubber spatula and a light hand to keep the air in the batter.
Divide the mixture evenly among prepared ramekins (fill about ¾ full, almost to the top).
Place ramekins on the hot baking sheet in the oven and bake for 20–25 minutes, or until puffed, golden, and just set in the centre.
Serve immediately for maximum puff! They’ll naturally deflate a little as they cool but will still taste AMAZING! Enjoy! Voila!