Mix the salt, pepper, onion powder and red pepper flakes in a bowl. Rub the pork with the mixture. Place the pork inside (fatty side up) a brown paper bag lined with one sheet of aluminum foil. I used brown paper bag I got from grocery store. Close the bag by folding it down. Place the bag on a rimmed baking sheet and roast until an instant-read thermometer read 185-190 F, about 4 hours or maybe a bit longer depending on your oven
Remove the pork from the bag, reserving any juices in the bag. When the pork is cool enough to handle, shred it into large pieces and toss it with the juices in the bowl
Making the crepes:
To make the crepes, place the eggs, milk, and 1/2 cup water, flour, 2 Tbsp melted butter in a blender until it's smooth. Cover and let it rest for 15 minutes up to 1 hour if you have the time
Heat a 12-inch nonstick skillet over medium-high heat. Coat it with a little melted butter, lower the heat, take the pan off the heat and pour in 1/3 cup crepe batter, swirling the skillet to spread it evenly over the bottom and place it back on heat. Cook for about 2 minutes, until the underside has golden brown spots all over; then flip and cook until speckled on the other side, about 1 minute. Repeat to make the remaining crepes. Stack the crepes on the plate
Put a crepe back in the skillet, and fold it in half. Scatter 1/4 cup of the cheese across the center of the crepe, and top it with 1/3 cup pork. Then drizzle with some mustard and tabasco, and add some pickles over the top if you want. Fold one corner of the crepe just over the filling; then roll the crepe to make a closed package. Repeat with the remaining crepes and filling
Serve immediately with some extra mustard and tabasco on the side