Sourdough Brioche Pretzel Buns:

1. Follow the instructions in the provided link to make the Sourdough Brioche Pretzel Buns. Begin by feeding the sourdough 2 days before you plan to make the buns. Follow the detailed recipe at forthepleasureofeating.com.

Peach BBQ Sauce (If using):

1. Follow the recipe at forthepleasureofeating.com to make the Peach BBQ Sauce with Malt.

Black Garlic Aioli:

1. In a slim jar or container, layer egg, Dijon mustard, balsamic vinegar, liquid smoke (if using), and lemon juice.
2. Top with all the oil.
3. Using a stick blender equipped with the whisking disc, blend on full speed without moving for a few seconds until mayonnaise forms at the bottom.
4. Gradually tilt and move the blender upwards until all the oil is incorporated.
5. Mash or chop black garlic and regular garlic, chop herbs, and add them to the mayonnaise with salt and pepper.
6. Blend again with the pureeing attachment until smooth.
7. Taste and adjust seasoning. Keep refrigerated in a lidded container for up to 3 days.

Black Garlic Butter with Lemon:

1. In a food processor, combine unsalted butter, mashed black garlic, minced fresh garlic, chopped parsley, chopped dill, kosher salt, lemon zest, and freshly ground pepper.
2. Mix until smooth.
3. Transfer to a serving dish or roll into a log shape using plastic wrap.
4. Refrigerate for at least 1 hour to firm up the butter.

Toppings:

1. Prepare toppings by slicing pickles, tomatoes, and onions, and washing lettuce.
2. Fry Serrano ham or bacon until crispy, if using, and keep warm in the oven.

Burger Patties:

1. Optionally caramelize chopped onions in a pan with olive oil until golden.
2. In a medium bowl, soak large baguette pieces in water or milk.
3. In a large bowl, combine pork and beef mince, eggs, Dijon mustard, dried parsley, salt, and pepper.
4. Squeeze moisture from the soaked baguette and add it to the meat mixture.
5. Mix by hand until a uniform dough forms.
6. Heat a pan with oil and form thin, irregularly shaped patties with your hands.
7. Fry patties until cooked through and crispy at the edges.

To Serve:

1. Reheat burger buns by sprinkling with water and baking at 350°F/175°C for 5-10 minutes in the air fryer or oven.
2. Slice buns horizontally and spread Black Garlic Butter with Lemon on each side.
3. Briefly fry in a hot pan until golden or place under the oven grill.
4. Top both sides with Black Garlic Aioli.
5. On the bottom side, stack lettuce, a hot burger patty, and desired toppings.
6. Drizzle with Peach BBQ Sauce.
7. Add the top half of the bun and enjoy your Pretzel Burger with Black Garlic Aioli!