Step 1

In a large skillet, heat olive oil over low to medium heat. Once the oil is hot, add the sliced onions. Allow the onions to cook and caramelize slowly for about 20 minutes, stirring occasionally. You'll want them to be a deep golden brown color.

Step 2

Reduce the heat to low. Stir in the beef broth, salt, pepper, garlic, and butter. Slowly pour in the heavy cream and stir until combined. Allow the sauce to simmer 5 to 10 minutes.

Step 3

Cook the pasta according to package directions to al dente. Drain but reserve 1 to 2 cups of the pasta water.

Step 4

Add the pasta to your caramelized onion sauce and stir. Add a little pasta water if the mixture is too thick. Taste and add more salt, pepper, or garlic if needed. Cover and simmer on low for 5 to 10 minutes.

Step 5

Uncover, stir, garnish, and serve.