Over the bowl of a stand mixer, carefully separate yolks and whites; transfer the yolks to a medium bowl. Let the whites rest for 20 to 25 minutes while cooking the topping (egg whites volume increase when they stand at room temperature).
In a deep saucepan over medium heat, melt 2 tbsp. butter. When it starts sizzling, add onions and sauté for 1½ minutes. Add peppers and sauté for 2 minutes.
Add chorizo sausage and cook for 1 minute. Add mushrooms and sauté for 2 minutes. Stir in Ro*Tel, freshly ground black pepper, hot sauce and paprika; cook for 5 minutes and keep warm until needed.
Meanwhile, add cream of tartar to the egg whites and on high speed with the whisk attachment, whip egg whites until stiff peaks form – DON’T over whip.
While whites are whipping, add salt to the egg yolks. Using a hand mixer, process yolks on high speed until well mixed.
Slowly pour the yolks over the whites. Using a spatula, gently fold them until well blended.
Preheat oven to 350ºF.
In a large shallow ovenproof saucepan over medium-high, melt 1 tbsp. butter. When it gets very hot, gently pour in the egg mixture and using a spatula, level out the surface. Reduce the heat to medium and cook for 4 to 5 minutes or until the bottom is lightly brown.
Take a spatula and carefully release the soufflé from the sides of the pan before transferring to the preheated oven; bake for 4 minutes.
Remove the soufflé from the oven and quickly but carefully spoon the topping mixture over; even it out with a spatula. Sprinkle the top with cheese and parsley.
Return the omelet to the oven and bake for an additional 6 to 8 minutes.
Remove from the heat (*see footnote) and quarter the soufflé omelet; serve immediately.