1) Mix together beef, onion, bell pepper, garlic, coriander, oregano, soy sauce, Worcestershire sauce, a scant 1/2 teaspoon salt, and 1/2 teaspoon pepper. Form into 4 (4 1/2-inch-wide) patties.
2) Heat a large griddle or 12-inch heavy skillet over medium heat until hot, then lightly toast buns.
3) Oil the griddle, then cook the patties for about 8 minutes for medium-rare, turning once. Transfer to the toasted buns.
4) Mix together the cabbage, carrot, and 1/4 teaspoon salt, then cook, turning occasionally, until slightly wilted, about 2 minutes. Divide among burgers.
5) Oil the griddle again and sear the onion and tomato for about 2 minutes, turning once, until slightly charred. Divide between the burgers.
6) Stir the tomato ketchup, mayonnaise, and mustard together and top burgers with sauce.
For the plantains:
1) While the hamburgers are cooking, peel the plantains and wrap them in foil.
2) Place the wrapped plantains on the grill and cook until tender but still firm and slightly caramelized.
3) Once cooked, remove from the grill, and slice into 1/2-inch diagonal rounds.
4) In a small bowl, mix together the yogurt, mayonnaise, and chipotle peppers until smooth.
5) Return the sliced plantains to the grill, and brush chipotle sauce on 1 side. Turn after a couple of minutes and brush the sauce on the other side.
6) Remove from grill and serve with the burgers.