In a bowl add the vegetable oil, red curry paste, tamarind pulp, coconut milk, brown sugar, fish sauce, minced garlic, salt, and all-purpose rub. Mix until well combined.
Preheat a camp oven or smoker to 300 degrees F (150 degrees C).
Cube the pork butt into large chunks, about 2 inches (5cm) in size.
Line a foil pan or baking dish with two of the banana leaves. Size the dish and leaf to match the amount of pork to be cooked.
In the banana leaf lined pan add the Kaffir lime leaves, Jalapeno, and lemongrass, then top with the pork.
Pour the red curry paste over the pork then give a gentle stir to combine the flavors.
Place the third banana leaf on top of the pork then cover the entire dish with foil.
Place the prepared tray in the preheated camp oven and cook until the pork is probe tender; about 2 1/2 to 3 1/2 hours. Tip: When you open the foil to check for tenderness, be careful not to burn yourself from the steam.
Remove the lemongrass and Kaffir lime leaves from the tray.
The large pieces of pork may be served as is or shred the pork to combine all the flavors together. Taste and season as/if necessary.
Serve with your favorite Thai red curry pork sides such as steamed rice or corn tortillas.