Diner-style omelettes are made for stuffing, but you can't just throw chopped vegetables into them willy-nilly and hope for the best. Omelettes cook fast—far too fast for fillings to do much beyond warm up a bit. So the key to great filled omelettes is to cook your fillings beforehand and have them warm and ready to go. Par-cooking the filling while the salted eggs rest is a good way to do it. Your imagination (and perhaps the local laws in your jurisdiction) are the only limits to what you can shove into an omelette, but here's a list of ingredients to get you started.
This chart is excerpted from my book, The Food Lab: Better Home Cooking Through Science.
|INGREDIENT||HOW TO PREPARE|
|Young cheeses of all kinds (I like cheddar, Jack, blue, feta, Gruyère, Brie, and goat cheeses)||Grate or crumble. If using in conjunction with other cooked ingredients, toss with them in a small bowl after par-cooking them; the residual heat will help start the melting process.|
|Hard grating cheeses like Parmigiano Reggiano, Cotija, and Pecorino Romano||Grate on a Microplane and add to the raw eggs.|
|Cured meats like sausage, ham, and bacon||Cut into 1/2-inch pieces or nuggets and par-cook in butter (let bacon cook in its own fat) until crisp on the edges and well browned.|
|Firm vegetables like onions, shallots, bell peppers, and hot peppers||Dice and soften in butter.|
|Tomatoes||Dice, salt, and drain.|
|Tender leafy vegetables like spinach and arugula||Sauté in butter, with a bit of minced garlic if desired.|
|Tender squashes like zucchini and summer squash.||Sauté in butter.|
|Asparagus||Cut into 1/4-inch slices on the bias and sauté in butter.|
|Scallions||Thinly slice whites and sauté in butter; thinly slice greens and incorporate into the filling or reserve for garnish.|
|Mushrooms||Slice thin and sauté in butter until the moisture has evaporated and the mushrooms are well browned.|
|Herbs||Add directly to the raw eggs.|
Some of my favorite omelette combinations are spinach with feta, asparagus and shallots with Gruyère, and onions, peppers, and ham with cheddar cheese. All classics, all delicious.
Melting Cheese in Omelettes
Here's a perennial omelette problem: You want the cheese in the center to be warm and melted, but by the time the cheese melts, the eggs are overcooked. Conversely, you can have perfectly tender curds of egg, but barely melted cheese. What's the solution?
The trick is to give the cheese a head start in melting by mixing it with hot ingredients.
For instance, for this ham and cheese omelette, I start by sautéing chunks of ham in butter until nicely browned, then I drop them directly into a bowl with grated cheddar cheese.
By the time the mixture gets into the omelette, that cheese is already warm and beginning to melt, so it only takes a little extra heat from the pan to get it nice and gooey. Best of both worlds.
How to Make a Bacon, Asparagus, and Gruyère Omelette
As with pizza toppings, the key to making an omelette that really works is to show restraint. Try to limit your filling combinations to one or two main ingredients, one cheese, and one herb, with perhaps some aromatics like garlic or onions added to complement the main ingredient.
The other real key is to make sure that you cook your ingredients properly—green vegetables ought to be tender-crisp, meats should be browned, and everything should be hot enough to give the cheese a jump start on melting.
For an asparagus, bacon, and Gruyère omelette, for instance, I start by first salting my beaten eggs, then sautéing the bacon in the same skillet I'm going to use for the omelette, cooking the bacon until it's nicely crisped and browned. Then I add some asparagus that I've thinly sliced on the bias, along with some shallots, sautéing it all until the asparagus is tender and the vegetables start to take on some color. I immediately transfer it to a bowl with grated Gruyère cheese.
Next, I cook my eggs just like in my standard diner-style omelettes: I melt and brown some butter; add the salted, beaten eggs; then cook them by pulling the set curds toward the center of the pan and tilting the pan to allow the wet eggs to flow under and fill in the spaces. This delivers large, tender, moist, and fluffy curds in the finished omelette, with a nicely browned surface.
Finally, I finish up by adding my filling to half of the omelette, turning off the heat, and covering the whole thing with a lid to allow the eggs to very gently finish cooking through while the cheese melts. You can be fancy and fold the omelette by sliding it onto a plate and flipping it with the lip of the pan, but it's easier to just use a spatula inside the pan itself, turning the omelette out onto a plate after it's already been folded.
Oh, and don't forget the most important ingredient in any omelette: the hot sauce.