In a large skillet, cook 4 slices of bacon over medium heat for about 6-8 minutes, turning occasionally, until they’re crispy and golden brown. Remove the bacon and place it on paper towels to drain any excess grease.

Remove excess grease from the skillet, leaving about a tablespoon for flavor, and reduce the heat to medium-low. Add 1 sliced large onion and cook for 10-15 minutes, stirring occasionally, until the onions are soft and a deep golden brown.

Pour in 1/2 cup of Irish stout into the skillet with the caramelized onions. Increase the heat to medium, allowing it to simmer for about 5 minutes until reduced by half. Season with salt and pepper to taste.

In a mixing bowl, combine 1 pound of ground beef with 1 tablespoon of Worcestershire sauce, salt, and pepper to taste. Mix gently and form into 4 equal patties.

Heat a grill or skillet over medium-high heat. Add the patties and cook for about 3-4 minutes on each side. In the last minute, add 1/2 cup of grated cheddar cheese on top of each patty.

While the burgers are cooking, prepare the sauce by mixing 1/2 cup of sour cream and 2 tablespoons of Dijon mustard in a separate bowl.

In a small skillet, melt some butter over medium heat. Toast the brioche burger buns cut-side down until golden brown, about 2-3 minutes.

To assemble, layer the bottom of the toasted brioche bun with a patty, caramelized onions, 2 slices of bacon, a dollop of sauce, and the bun top.

Serve your Irish Pub Burgers hot, paired with fries or chips if desired.