Step 1: Prepare the Burger Patties

1. In a large bowl, combine 1 lb ground beef, 1 tbsp Worcestershire sauce, 1 tsp salt, and ½ tsp black pepper. Mix gently until just combined to keep the patties tender.

2. Form into 4 equal patties, slightly larger than the buns (about 4 inches wide) to account for slight shrinkage. Create a small indent in the center of each patty to prevent puffing during cooking.

   • Tip: Handle the beef lightly to avoid dense patties. Make the indent about ¼ inch deep with your thumb or a spoon.

Step 2: Slow Cook the Patties

1. Place the patties in the slow cooker, stacking if necessary but ensuring they’re not tightly packed. Add ¼ cup beef broth or water to keep them moist.

2. Cover and cook on low for 6-8 hours or high for 3-4 hours, until the internal temperature reaches 160°F (71°C) for medium-well (or 140°F/60°C for medium, if finishing with a sear).

   • Tip: Check temperature early to avoid overcooking. The slow cooker keeps patties juicy, but a meat thermometer ensures perfect doneness. Reserve any liquid for another use (e.g., gravy).

Step 3: Cook the Bacon

1. While the patties cook (or near the end), heat a large skillet over medium heat. Cook 4 slices of bacon until crispy, about 3-4 minutes per side.

2. Remove bacon to a paper towel-lined plate to drain. Reserve 1-2 tbsp bacon grease in the skillet for the onions.

   • Tip: Cook bacon in batches if needed to avoid crowding. Crumble or keep slices whole for topping, depending on preference.

Step 4: Sauté the Onions

1. In the same skillet with reserved bacon grease, add 1 large sliced onion. Cook over medium heat, stirring occasionally, until soft and caramelized, about 10-15 minutes.

2. Pour in ½ cup Irish stout and simmer until the liquid reduces by half, about 3-5 minutes. Season with a pinch of salt and pepper, then set aside, covered, to keep warm.

   • Tip: Slice onions thinly for even caramelization. Stir frequently to prevent burning. The stout adds a rich, slightly bitter depth.

Step 5: Optional Post-Cook Sear

1. For a grill-like crust, heat a skillet or grill pan over medium-high heat with 1 tsp olive oil. Remove patties from the slow cooker, pat dry, and sear for 1-2 minutes per side until golden.

2. During the last 30 seconds, sprinkle 2 tbsp grated cheddar cheese on each patty to melt. Skip this step if you prefer the tender, slow-cooked texture.

   • Tip: Ensure the skillet is hot for a quick sear without overcooking. Use a cast-iron skillet for the best crust.

Step 6: Prepare the Sauce

1. In a small bowl, mix ½ cup sour cream, 2 tbsp Dijon mustard, and a pinch of salt until smooth. Set aside at room temperature or refrigerate if preparing early.

   • Tip: Adjust mustard to taste for more tang. Add a dash of stout or lemon juice for extra depth if desired.

Step 7: Toast the Buns

1. Heat a clean skillet over medium heat. Spread a thin layer of butter (about ½ tbsp per bun) on the cut sides of 4 brioche buns.

2. Toast the buns, cut-side down, until golden brown, about 1-2 minutes. Set aside on a plate, covered with a clean towel to keep warm.

   • Tip: Watch closely to avoid burning. Butter only the cut sides for crisp, golden results.

Step 8: Assemble and Serve

1. Place a cheese-topped patty on the bottom half of each toasted bun.

2. Top with a portion of caramelized onions, 1-2 bacon slices (whole or crumbled), and a generous dollop of sour cream-Dijon sauce.

3. Cap with the top bun and serve immediately with fries, chips, or a side salad for a complete pub experience.

   • Tip: Press buns gently to secure toppings. Serve with extra sauce on the side for dipping, and pair with a pint of Guinness for authenticity!