1. Preheat grill to medium high. Meanwhile, rub onion and chicken with the olive oil. Sprinkle both with the rub and rub it into the surface of each.
2. Grill onions and chicken, covered, over medium-high heat until onions are tender and grill-marked, about 6 minutes per side, and chicken is grill-marked and cooked through, about 7 minutes per side. Transfer onions and chicken to a plate, cover loosely with foil, and let rest for about 5 minutes.When they are cool enough to handle, roughly chop onions and transfer to amedium bowl. Slice the chicken very thin, and set aside.
3. Add tomatoes, garlic, lime juice, jalapeños, avocado, and cilantro to the chopped onions and stir to combine.
4. Wrap 2 stacks of 4 tortillas each in foil and heat on the grill until warm and pliable, about 2 minutes. Transfer warm tortillas to a work surface. Fill each tortilla with a few slices of chicken and a portion of the tomato-avocadosalsa. Fold the filled tortillas, and garnish with lime wedges, if desired. Serve immediately, with any remaining salsa in a bowl on the side.
Source: fresh magazine July, August 2010