Set all of the other brunch dishes out before you start making omelets. Then make omelets to order for those guests that want them.
Grate a few cups of cheese ahead of time. You can use any type of cheese you like. If there's any leftover cheese, wrap and refrigerate for another use.
Wash, cut and sautee a few cups of mushrooms. Any leftover mushrooms can be served as a side dish or refrigerated and added to a casserole or stew. Of course, you can add other types of veggies if you like. Simply cut into small dice and fry until soft. Then add to omelets in place of mushrooms.
Beat eggs, milk, salt and pepper together with a whisk.
Place a skillet over medium heat. Melt butter. Coat the skillet with the butter.
Add egg mixture and cook until the eggs begin to set on the bottom.
Use a spatula to lift the edges of the omelet so that the uncooked part of the eggs flows under and cooks.
Continue cooking the center of the omelet looks dry.
Sprinkle 1/3 cup cheese and 1/3 cup sauteed mushrooms into the center of the omelet.
Use the spatula top fold one edge of the omelet over the vegetables.