Use a sharp chef's knife and cutting board to thinly slice the radishes into rounds or matchstick strips, displaying their crisp, round appearance.
Place the mixed salad greens in a large mixing bowl. Add the sliced radishes on top.
In a small bowl or jar, combine olive oil, apple cider vinegar, salt, and black pepper. Whisk or shake until the dressing is emulsified and well-blended.
Drizzle the dressing evenly over the salad, then toss gently with salad tongs or a large spoon until the greens and radishes are coated and evenly distributed.
Serve immediately in individual bowls or on a platter, showcasing the fresh, bright colors and crunchy textures of the radishes and greens.