Melt butter in olive oil in a large (7 quart) Dutch oven over medium heat. Add the onions, ⅛ teaspoon salt and ⅛ teaspoon pepper.

Cook, stirring occasionally, until onions are caramelized and dark golden brown, about 30-35 minutes. Turn down the heat and/or add additional butter/olive oil if the onions start to scorch.

Once the onions are caramelized, add the garlic, red pepper flakes, soy sauce and Worcestershire sauce and cook for 30 seconds.

Add the water and half of the evaporated milk. Whisk the cornstarch with remaining evaporated milk and add to the pot.

Increase heat to high to bring to a boil while you stir in the beef bouillon and remaining herbs and seasonings.

Once boiling, add the pasta and reduce to a simmer over medium-high heat for 20-25 minutes (uncovered) OR until al dente, stirring often so the bottom doesn’t burn.

Once the pasta is done cooking, it should still have some excess liquid (that will become the sauce).

Remove the pan from the heat and stir in the Gruyere cheese a handful at a time until melted, followed by the Parmesan until melted.

Taste and season with salt and pepper if desired. If you would like a saucier pasta, stir in additional water or milk. Garnish with fresh parsley if desired.