Make dressing by combining the ranch dressing and salsa in a bowl. Stir. Cover and refrigerate.
Next, make the chicken: Generously season both sides of the breasts. Heat the oil and butter in a large skillet over medium-high heat. Cook the chicken on both sides until deep golden brown on the outside and done in the middle, about 5 minutes per side. Remove and set aside to cool, then cut it into cubes.
Cook corn according to package directions.
To assemble the salad, pile shredded lettuce, chicken, tomatoes, cheese, corn, green onion, cilantro, and crushed chips on a big platter. Drizzle the dressing all over the top. Serve in individual bowls.