1. Preheat your oven to 350°F (175°C).
2. In a large skillet, heat the olive oil over medium heat. Add the onions and cook until they are caramelized, about 25-30 minutes. Stir frequently to prevent burning, and add a splash of water if they start to stick.
3. Add the garlic to the onions and cook for an additional 2 minutes until fragrant. Remove from the skillet and set aside.
4. In the same skillet, add the beef cubes. Season with salt and pepper, and brown on all sides. This should take about 8-10 minutes.
5. Once the beef is browned, add the red wine to deglaze the pan, scraping up any bits stuck to the bottom. Cook for 2-3 minutes until the wine reduces slightly.
6. Return the onions to the skillet, and add the beef broth, thyme, and bay leaf. Bring to a simmer and cook for 15 minutes, allowing the flavors to meld.
7. Remove the bay leaf and transfer the beef mixture to a large casserole dish. Arrange the slices of French bread on top, covering the beef mixture completely.
8. Sprinkle the shredded Gruyère cheese over the bread slices, ensuring an even layer.
9. Bake in the preheated oven for 20-25 minutes, or until the cheese is bubbly and golden brown.
10. Let it cool for a few minutes before serving, allowing the flavors to settle.

As Mama Lou always said, “The secret to a perfect dish is in the patience and love you put in it.” Take your time with each step, savoring the process as much as the final product.