In a large skillet over medium-high heat, heat oil. Add chicken and season with salt and pepper. Cook until golden and no longer pink, 8 minutes per side. Let rest 5 minutes, then slice.
Line a surface with a large square of parchment. Fold up bottom corner to make a triangle. Cover paper with 3 leaves romaine and top with 2 slices provolone, tomato, 2 slices bacon and cooked chicken slices, then drizzle with ranch and season with salt and pepper. Top with romaine leaf.