Slice the yellow onions into 1/8-inch thick rings and set aside.

In a large pot, heat olive oil and butter over medium heat, add onions with a pinch of salt, and cook for 30-35 minutes until caramelized.

Stir in minced garlic and red pepper flakes, then add Worcestershire sauce and soy sauce, cooking for another 30 seconds.

Pour in 4 cups of water and half of the evaporated milk, whisk cornstarch with remaining milk, then add to pot with beef bouillon and herbs.

Bring to a boil, add orecchiette, reduce heat to simmer, and cook uncovered for 20-25 minutes until pasta is al dente.

Remove from heat and stir in Gruyere and Parmesan cheese until melted and creamy.