In a nonstick skillet, over medium heat, add chopped bacon and sliced mushrooms. Cook for 5–7 minutes until the bacon is crispy and the mushrooms are tender.

In a mixing bowl, thoroughly whisk together the eggs and a pinch of salt until well combined and slightly frothy. Set the egg mixture aside.

Melt 1 teaspoon of butter in the same skillet over medium-high heat. Pour half of the egg mixture into the skillet and cook for about 3–4 minutes.

When the egg is almost fully cooked, spoon half of the bacon and mushroom mixture onto one side of the omelet. Carefully fold to create a semi-circle.

In a small saucepan, melt 1 tablespoon of butter over medium heat and stir in the flour until smooth. Gradually whisk in the milk until it thickens, about 2–3 minutes.

Remove from heat and stir in the shredded cheddar and Parmesan cheese, along with taco seasoning, until melted and well combined.