French Onion Dip Sandwiches (Slow Cooker)

Begin by caramelizing the onions: Heat 3 tablespoons of olive oil in a large, deep pot over medium heat. Add the thinly sliced onions and toss to coat evenly. Cook, stirring frequently, until softened (approximately 15 minutes). Incorporate 1 tablespoon of butter and continue cooking, stirring occasionally, until the onions deepen in color and begin to brown beautifully (about 15 minutes).

Enhance the caramelized onions: Stir in the sugar and 1/2 teaspoon of salt. Continue to cook, stirring infrequently, until the onions are richly browned (10 to 15 minutes). Introduce the minced garlic and cook for another minute, allowing its aroma to infuse the onions.

Deglaze and simmer: Add 3 tablespoons of water to the pot, scraping up any flavorful bits from the bottom. Simmer for 3 minutes. Repeat this process with the remaining 3 tablespoons of water, simmering for another 3 minutes. Pour in the dry vermouth, scraping the bottom and sides of the pot to release any remaining caramelized goodness. Cook for 4 minutes.

Create the broth: Introduce the beef stock, Worcestershire sauce, soy sauce, fresh thyme, and bay leaf. Simmer gently for 10 minutes, ensuring it doesn't boil. Add the black pepper. Remove from heat, discard the bay leaf, and allow the soup to cool slightly before transferring it to your slow cooker.

Prepare the rump roast: Trim any excess fat from the rump roast and generously season all sides with salt and pepper. In the same pot (after a quick wash), heat the remaining 2 tablespoons of olive oil over high heat. Sear the meat on all sides until nicely browned, approximately 10 minutes. Carefully transfer the seared meat to the slow cooker, nestling it in the onion soup.

Slow cook to perfection: Spoon the soup over the meat, ensuring a generous topping of onions. Cover and cook on Low for 4 hours.

Shred and continue to cook: Remove the meat from the slow cooker and slice it diagonally against the grain. Return the slices to the slow cooker, allowing them to soak in the savory broth. Continue to cook on Low for an additional 2 hours.

Prepare the rolls: Preheat your oven to 350 degrees F (175 degrees C). Spread the split French rolls with the remaining 2 tablespoons of butter. Place the rolls face-down on a baking sheet and bake until they begin to brown (8 to 10 minutes).

Add cheese: Remove the rolls from the oven, flip them, and sprinkle generously with grated Gruyère cheese. Set the oven rack about 6 inches from the heat source and turn on the broiler. Broil until the cheese is melted, bubbly, and lightly browned (2 to 4 minutes).

Assemble and serve: Using a slotted spoon, remove the tender meat from the slow cooker and arrange it generously on the prepared rolls. Serve the flavorful broth on the side for dipping.