Wash all produce thoroughly. Remove stalks and tough outer layers from the fennel bulb, then slice thinly.

Peel the oranges, removing all white pith, and cut them into segments.

Thinly slice the red onion.

In a large bowl, combine sliced fennel, orange segments, red onion slices, and mint leaves.

Drizzle olive oil over the mixture and season with salt and pepper; toss gently to combine.

Serve immediately for the best flavor and freshness.