This omelet is baked on a 10x15 inch cookie sheet. This might sound like an obscure size, but I bet you have one in your cupboard. It’s often referred to as a Jelly Roll pan, but it’s just a small, lightweight cookie sheet. -this recipe is seasoned with soy sauce, but any salty sauce will work. I often use some fish sauce instead but realize that fish sauce isn’t a pantry staple for most people. You can use a little Worcestershire too, if you like. Good old fashioned salt does the trick as well. -The omelet keeps well in the fridge for a day or two and makes great leftovers
- Preheat oven to 350ºF. Coat a 10x15-inch jelly roll pan with nonstick cooking spray or brush with 1 tsp canola oil and line it with parchment paper. Pro Tip: gently scrunch the parchment into a ball, and then smooth it out again. Doing this will allow the parchment to lay flatter and sit nicer in the creases and corners of the pan. Allow an overhang of 1 inch on all sides, and lightly spray or brush the top of the parchment paper with oil (1 tsp would be sufficient). Set aside.
- In a skillet over medium heat, add remaining 2 tsp canola oil and sauté onions until just starting to soften, then add the peppers. Sauté for 1-2 minutes, or until desired doneness of veggies. I prefer a little crispness to my peppers, so I don’t tend to cook them too long. Remove from heat and allow to cool slightly.
- Place the flour in a small bowl and slowly pour the milk over the flour in a steady stream. Whisk until smooth and ensure there are no lumps.
- In a medium bowl, whisk together the eggs, mustard, soy sauce, and pepper. Add the milk mixture and whisk for about 2-3 minutes, or until it has some medium to large sized bubbles. Pour the mixture into the prepared sheet and evenly sprinkle with the sautéed onions and peppers, chopped kielbasa and 1/2 cup of the cheese over the top.
- Bake for about 12 minutes, until the edges are set and the center is beginning to set (it will still be a little wobbly). Remove from the oven, sprinkle 1 cup of cheese on top, and bake for another 5 to 6 minutes, until the cheese is just melted and the center has set. Remove the pan from the oven and let cool for about 5 minutes.
- Once the omelet and pan have cooled slightly, gently lift the long end of the parchment paper and tightly roll the omelet to create a long cylinder. Sprinkle with the remaining 1/2 cup cheese and the green onions.
- Slice and serve warm.