Make this the day before or early in the morning the day of making the sandwiches. Best if used chilled.
To make, boil water with sugar and vinegar. Let boil for 3 minutes to dissolve sugar; remove from heat.
Place sliced veggies into a large mason jar. Once boiled mixture has cooled slightly, pour over veggies in jar. Then close lid tightly and place in fridge for 6-8 hours, or longer.
Whisk mayonnaise ingredients together; refrigerate. Reminder: Adjust levels of sriracha according to taste.
Before prepping meat, in a small bowl mix together the marinade ingredients, excluding the oil. Set aside.
Start slicing pork roast. Using a serrated knife allows to slicing pretty thin. You want it about 1/4 inch thick. (Not so thin it’s falling apart, but not so thick that it will get tough when it cooks.) The pieces will cook down a bit, so make them a little longer and wider than you’d want on a sandwich.
Place sliced pork into a heavy duty ziploc bag. Pour marinade on top; refrigerate for 4-6 hours.
Set out a large skillet; pour about 3-4 tablespoons vegetable or canola oil on bottom of skillet.
Turn heat to medium high to heat oil. Meanwhile, lay out a large baking sheet lined with paper towels.
Once oil has heated, remove pieces of pork one-by-one with tongs from ziploc bag and slowly place into oil (you want oil to sizzle when you place meat in, but if it pops too much, turn heat slightly down).
Flip meat over to cook both sides evenly. Once edges start to brown, remove from pot with tongs and set on paper towel lined baking sheet.
Sear meat in batches until it’s all cooked. Let rest on baking sheet while you assemble the other sandwich ingredients.
Start assembly by slicing baguettes or french rolls. Spread spicy mayo on bottom side of roll.
Place several slices of meat over the mayo, then layer with pickled veggies, fresh cucumbers, jalapeño and fresh cilantro.