Preheat your oven to 300°F (150°C). Score the skin of the pork belly in a crosshatch pattern, being careful not to cut too deep into the meat. Rub the pork belly all over with salt, black pepper, smoked paprika, garlic powder, and onion powder.

Slow Cook

Place the seasoned pork belly in a roasting pan and pour the apple cider vinegar over it. Cover the pan with aluminum foil and cook in the preheated oven for about 3 hours, or until the meat is tender and easily pulled apart.

Crisp the Skin

After 3 hours, remove the foil and increase the oven temperature to 450°F (230°C). Roast for an additional 30 minutes, or until the skin is crispy.

Rest the Meat

Remove the pork belly from the oven and let it rest for 15 minutes before slicing.

Preparing Pickled Vegetables

Slice the Vegetables

While the pork belly is cooking, thinly slice the carrots, cucumber, and red onion.

Make the Pickling Brine

In a saucepan, combine the white vinegar, water, sugar, salt, black peppercorns, and mustard seeds. Bring to a boil over medium heat, stirring until the sugar and salt dissolve.

Pickle the Vegetables

Once the brine is boiling, remove from heat and pour it over the sliced vegetables in a jar. Let the jar cool to room temperature, then refrigerate for at least 1 hour before using.

Assembling the Sandwich

Prepare the Buns

Slice the brioche buns in half and lightly toast them if desired.

Layer the Ingredients

On the bottom half of each bun, add a generous portion of sliced pork belly, top with pickled vegetables, fresh cilantro, and a drizzle of sriracha sauce.

Complete the Sandwich

Place the top half of the bun on the sandwich and serve immediately.