Into a large bowl, break jackfruit into pieces. Add soy sauce, pineapple juice, and liquid smoke, and toss to coat. Sprinkle in salt and pepper and toss once more.
In a large pan over medium-low heat, warm oil. Add jackfruit and increase heat to medium-high. Cook 7 minutes, or until jackfruit is browned, gently breaking apart into a pulled pork style texture. Remove from heat.
Layer inside sweet buns and serve.
