Generously season the beef short ribs with salt and pepper. In a large Dutch oven, heat 2 tablespoons of olive oil over medium-high heat. Sear the ribs for about 4–5 minutes on each side until they are beautifully browned, then set aside.

In the same pot, add 2 tablespoons of butter and another tablespoon of olive oil over medium heat. Add the sliced yellow onions, reduce heat to low, and cook, stirring frequently for 30–40 minutes until golden brown.

Stir in 2 minced garlic cloves and sauté for about 1 minute until fragrant.

Pour in 1 cup of dry red wine, scraping the browned bits from the bottom. Let it cook for about 3-5 minutes to reduce slightly.

Add 6 cups of beef stock, reserved short ribs, fresh thyme, and bay leaves. Bring to a gentle boil, then cover and simmer for 2.5 to 3 hours until tender.

Slice a French baguette and arrange on a baking sheet. Toast under the broiler for about 2–3 minutes until lightly golden. Top each slice generously with Gruyère cheese and broil until melted.

Once the short ribs are tender, remove the bay leaves and thyme stems. Ladle the soup into warm bowls and top with Gruyère toast. Serve piping hot.