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.
Serve immediately, topped with tortilla strips.