Preheat the broiler. Line a small baking sheet or roasting pan with foil. Place the tomatoes, onion, and garlic cloves on the foil; set under the broiler 3 to 4 inches from the heat, and broil for 4 to 5 minutes until charred on one side. Flip over and broil for another 4 to 6 minutes until the skin is blistered and completely charred; the tomatoes should be very soft with the juices beginning to emerge. Remove from heat.

Once they are cool enough to handle, quarter the tomatoes and place in a blender, along with any juices in the pan. Peel the garlic cloves and add to the blender. Add the onion, salt, and 1 cup of the broth and puree until completely smooth.

In a casserole or soup pot, heat the oil over medium heat until hot but not smoking. Pour in the puree, cover partially, as the sauce will sizzle, and cook, stirring occasionally, for 7 to 8 minutes, until the sauce thickens and darkens considerably.

Meanwhile, combine the grapefruit juice, orange juice, lime juice, vinegar, oregano, allspice, cumin, pepper, achiote paste, and the remaining 1 cup of broth in the blender and puree until completely smooth.

Stir the juice mixture into the tomato sauce, bring to a simmer, and simmer for 5 minutes.

Add the chicken, stir together well, and cook, uncovered, until the meat has absorbed most of the sauce, about 5 minutes. The dish should be very moist but not soupy.

Serve with pickled onions and cabbage.