Heat the oil in a large skillet over medium heat. Add the onion and cook for 3 minutes, until tender. Add the carrot and bell pepper and cook for another 2 minutes. Add allspice and paprika, tossing to coat vegetables. Stir in ground beef. Season with curry powder, garlic powder, dried thyme, sugar, salt, and pepper. Cook, stirring and breaking up any lumps with wooden spoon, until the meat is nearly cooked through. Stir in the flour and panko bread crumbs. Add the water, and cook a few minutes more, until the liquid is absorbed. It should not be watery, yet still remain moist. Stir in chopped scallion. Remove from heat and set aside to cool.