Using the large holes of a box grater, grate the tomatoes and the onion into a bowl. Add the garlic, chile peppers and cilantro and stir to combine. Place half of the salsa in a plastic tub or storage container, season with a little salt, cover and store in the refrigerator. Place the remaining salsa in a large resealable plastic bag and add the EVOO. Sprinkle the chicken liberally with salt and pepper and add it to the bag, shaking it around to coat it with the marinade. Double-bag the chicken in case the first bag leaks. Marinate in the refrigerator for 30 minutes and up to 2 hours.
Preheat a grill or a grill pan to medium-high heat.
Meanwhile, melt the butter in a medium pot over medium heat. Add the rice and cook, stirring, until golden brown, 3 to 4 minutes. Add the reserved salsa and the chicken stock and bring to a boil. Reduce the heat to a simmer, cover and cook for 20 minutes. After about 5 minutes, place the chicken on the grill and cook, turning occasionally, for 12 to 15 minutes.
If you are using black beans, rinse and drain them, then reheat them in a small pan with the cumin and some salt and pepper. If you are using refried beans, reheat them in a small pan with the cumin, thinning them with a splash of water.
Cut the lime into wedges and douse the chicken with lime juice when it comes off the grill. Serve the chicken with the rice.