In a small bowl, whisk the olive oil, dressing mix and lemon juice together.
Place the chicken in baking dish. Pour the half marinade over the chicken to cover. Cover and let stand for 30 minutes.
Preheat the grill.
In a large bowl, combine the corn, bell pepper, tomato, green onion and jalapeño with the remaining marinade and toss until well coated. Remove the chicken from the marinade and discard and remaining marinade.
Grill the chicken for five minutes on each side or until juices run clear.
Serve the chicken immediately topped with the corn salsa.