Begin by slicing the yellow onions into ⅛-inch rings.

In a large Dutch oven, heat a mixture of olive oil and butter over medium heat. Add the sliced onions and stir regularly for about 30-35 minutes.

Once the onions are caramelized, stir in the minced garlic, red pepper flakes, Worcestershire sauce, and soy sauce.

Pour in the water and half of the evaporated milk, stirring well to combine. Add the cornstarch mixed with the remaining milk, beef bouillon, and fresh herbs.

Bring the mixture to a boil, then add your chosen pasta. Simmer gently for 20-25 minutes, stirring occasionally.

Once the pasta is cooked, remove from heat and stir in the grated Gruyere and Parmesan cheese until melted.