Step 1
Preheat the oven to 325 degrees F (165 degrees C).
Step 2
Season pork all over with rosemary and freshly ground black pepper.
Step 3
Stir flour salt egg white and water together in a large bowl until very smooth. Adjust with more flour it's too runny. Add pork shoulder and coat thoroughly.
Step 4
Spread a few spoons of excess \plaster\ into a baking dish or pan. Add fat-side up. Use a spoon to re-apply plaster to any spots that need it as well as to the top.
Step 5
Roast in the center of the preheated oven until the surface is dry and hard and an instant-read thermometer inserted into the center reads 185 degrees F (85 degrees C) about 3 1/2 hours.
Step 6
Let cool for 15 minutes to 1 hour. Break pork up into big chunks and transfer to plate. Add some of the pan juices that accumulated at the bottom of the pan. Cover with plastic wrap. Chill in the refrigerator 8 hours to overnight.
Step 7
Combine apple onion jalapeno cilantro salt lime juice and cayenne in a bowl for salsa.
Step 8
Slice chilled pork into strips and then cut into 1/2-inch cubes.
Step 9
Heat a dry nonstick pan over medium-high heat. Brown pork in the pan 3 to 5 minutes. Serve pork on warm tortillas with the salsa and lime wedges.