Open the can of black beans with a can opener and thoroughly rinse them under cold water to remove excess salt and liquid. Pour the beans into a large mixing bowl.
Finely chop the red onion and add it to the beans, giving the mixture a pungent crunch.
Chop the fresh cilantro finely and sprinkle over the beans and onion, adding a burst of herbal freshness.
Squeeze the juice of a lemon over the mixture, watching it brighten and turn slightly glossy as the citrus hits the beans.
Drizzle the olive oil over everything, coating the ingredients with a silky sheen and helping to meld the flavors.
Taste the salad and season with salt and pepper, adjusting until the flavors are bright and balanced.
Gently toss the salad to evenly distribute the herbs, lemon, and oil without breaking the beans. Let it sit for at least 10 minutes to allow the flavors to meld.
Give the salad a final stir, then serve at room temperature or chilled, garnished with extra herbs if desired. Enjoy this bright, hearty dish with minimal effort!