Step 1

Place a large skillet with flat sides over medium-high heat and add olive oil and butter. Stir in onions and cook for 15 minutes, stirring occasionally.

Step 2

Stir in garlic, salt, and pepper; cook an additional 5 minutes or until onions have browned and are jam-like in texture. Stir in sherry and scrape the bottom of the skillet to remove any brown bits on the bottom.

Step 3

Stir in water, beef broth,  thyme leaves, parsley, and Worcestershire sauce. Add broken linguine and stir to incorporate pasta into the liquid. Bring to a boil and boil for 10 minutes, stirring occasionally, until pasta is cooked and most of the liquid is absorbed. Remove from heat and cover for 3 minutes.

Step 4

Toss in grated Parmesan, Gruyere, and garnish with thyme sprigs and chopped parsley, if desired.