Mix chicken, garlic, ginger, turmeric, and salt together in a large bowl. Cover with plastic wrap and place in the refrigerator to marinate, about 30 minutes.
Heat vegetable oil in a wok or large pot over medium-high heat. Add onion; cook and stir until browned, 2 to 3 minutes. Add tomato, shrimp paste, tamarind paste, and chile powder; mix until flavors combine, about 1 minute. Stir in chicken with marinade. Cook until chicken is browned on both sides, about 5 minutes.
Stir chicken stock and sugar into the wok. Cover and simmer for 15 minutes. Add jackfruit; simmer until tender, about 15 minutes. Stir in curry powder. Continue simmering until the internal temperature of the chicken registers 165 degrees F (74 degrees C) on an instant-read thermometer, about 5 minutes more.