5 oz thinly sliced French bread (about 3 ½ cups), torn in half
1 cup shredded low-moisture mozzarella cheese
½ cup shredded gruyere cheese
Instructions
Heat 3 tablespoons of olive oil and the butter in a wide braiser pan or a large Dutch oven over medium-low heat. Add the onion, 1 ½ teaspoons of salt, and pepper; cook, stirring occasionally, until the onion is very soft and a deeply golden brown, 15 to 20 minutes. Add the mushrooms, thyme, and garlic and cook until the mushrooms begin to soften, 3 to 5 minutes.
Stir in the wine and cook until it is almost completely evaporated, about 2 minutes. Pour in the beef broth, 3 cups of water, and Worcestershire sauce. Bring to a boil over medium-high heat. Add the pasta and cook, stirring frequently until al dente, 10 to 11 minutes. Remove the thyme sprigs. Stir in the cream cheese and red wine vinegar.
Turn the broiler on high. Brush or drizzle the bread with the remaining 2 tablespoons of olive oil and sprinkle the remaining ½ teaspoon of salt. Top the pasta with the bread and sprinkle with the mozzarella and gruyere cheese. Broil until the cheese is deeply golden, 2 to 5 minutes, keeping a close eye on the pasta. Let it stand for 5 minutes before serving with extra thyme sprinkled on top.
