Heat olive oil in a medium skillet over medium high heat.
Season chicken breasts with salt and pepper, to taste. Add to skillet and cook, flipping once, until cooked through, about 3-4 minutes per side. Let cool before dicing into bite-size pieces.
To assemble the salad, place romaine lettuce in a large bowl; top with chicken, tomato, corn, beans, onion and cheeses. Pour Ranch dressing and BBQ sauce on top of the salad and gently toss to combine.