In a large pot, melt 2 tablespoons of butter and 2 tablespoons of olive oil over medium heat. Add the sliced yellow onions, stirring occasionally for 30-35 minutes until caramelized.

Stir in the minced garlic and red pepper flakes, sauté for about 30 seconds. Mix in Worcestershire sauce and soy sauce. Let simmer for an additional minute.

Pour in water and half of the evaporated milk. In a bowl, mix cornstarch with remaining evaporated milk, then add to pot and stir to combine.

Bring the liquid to a boil. Add the orecchiette pasta, reduce heat to simmer, cover, and cook for 20-25 minutes until pasta is al dente.

Remove from heat, stir in the Gruyere and Parmesan cheese until melted and creamy. Taste and adjust seasonings as needed before serving.