While the pasta cooks, heat the olive oil in a large skillet over medium heat. Once hot, add the chicken and onions and saute, stirring occasionally, until the chicken is browned and cooked through.
In a large bowl mix together barbecue sauce, sour cream and cheeses. Add hot cooked pasta to the bowl and toss well in the sauce. Add cooked chicken and onion. Add corn, black beans, tomatoes and lettuce and toss to combine. Serve immediately.