Start by seasoning the 2 lbs of beef chuck with salt and pepper. In a large Dutch oven, heat 2 tablespoons of olive oil over medium-high heat. Add the beef cubes in batches, browning them on all sides for about 5-7 minutes. Once browned, remove the beef from the pot and set it aside on a plate.

In the same pot, add the 4 large, thinly sliced onions and cook over medium heat, stirring frequently. This should take about 20-25 minutes, as you want the onions to become beautifully caramelized and golden brown. In the last 5 minutes, add 4 cloves of minced garlic to enhance the aroma and flavor.

Once the onions are caramelized, stir in 2 tablespoons of tomato paste and cook for an additional 2-3 minutes until fragrant.

Pour in 1 cup of dry red wine, using a wooden spoon to scrape the bottom of the pot and lift any browned bits. Let the wine simmer for about 3-5 minutes to reduce slightly.

Return the browned beef cubes to the pot, followed by 4 cups of beef broth, 2 teaspoons of fresh thyme leaves, and 2 bay leaves. Bring the mixture to a gentle simmer, then cover and reduce the heat to low. Let it cook for about 1.5 to 2 hours, or until the beef is incredibly tender.

While the stew cooks, preheat your oven to 350°F (175°C). Take a loaf of crusty bread and slice it into thick pieces. Arrange these slices on a baking sheet.

Once the stew is finished cooking, carefully remove the bay leaves and taste for seasoning. Adjust with more salt and pepper if desired. Ladle the stew into oven-safe bowls or keep it in the Dutch oven for serving.

Top the stew with the thick slices of bread, overlapping them if necessary. Generously sprinkle 2 cups of shredded Gruyère and 1 cup of shredded mozzarella cheese over the bread.

Place the bowls or the Dutch oven in your preheated oven and bake for 15-20 minutes until the cheese is bubbly and golden.

After baking, remove the dish from the oven and sprinkle with 2 tablespoons of freshly chopped parsley for a burst of color and fresh taste.