Season the chicken pieces with green seasoning, salt, and black pepper, and allow to marinate for at least 30 minutes.
Heat vegetable oil in a heavy-bottomed pot or dutch oven over medium heat.
Mix the curry powder with 4 tablespoons of water to create a thick paste, then add to the hot oil and fry for 2 to 3 minutes until the oil starts to separate.
Add the seasoned chicken to the pot, stirring thoroughly to coat every piece with the curry mixture, and cook for 8 minutes to brown.
Add the diced onions, minced garlic, and cubed potatoes to the pot, stirring to combine.
Pour in 2 cups of water and place the whole scotch bonnet pepper on top.
Reduce heat to medium-low, cover the pot, and simmer for 30 to 35 minutes until the chicken is cooked through and the potatoes are soft.
Remove the scotch bonnet pepper carefully to avoid bursting it, and crush a few potato cubes to thicken the sauce if desired.
Place one roti flat on a plate, spoon a generous portion of curry chicken and potatoes into the center, and fold the sides over to form a square wrap.