Prepare the oranges: Using a sharp knife, slice off the top and bottom of each orange. Stand an orange on one of its cut ends and carefully slice downwards, following the curve of the fruit, to remove the peel and white pith. Once peeled, slice the oranges into thin rounds, approximately 0.5cm (1/4 inch) thick. Set aside.

Toast the pistachios: Place the shelled pistachios in a dry skillet over medium heat. Toast for 3-5 minutes, stirring frequently, until fragrant and lightly golden. Be careful not to burn them. Remove from the skillet and let them cool completely. Once cooled, roughly chop them.

Prepare the red onion: If the red onion is very pungent, you can soak the thin slices in cold water for 10 minutes, then drain thoroughly. This will mellow its flavor. Otherwise, proceed with the drained, thinly sliced onion.

Make the dressing: In a small bowl or jar, whisk together the olive oil, lemon juice, honey (or maple syrup), salt, and black pepper until well combined and emulsified. Taste and adjust seasoning if necessary.

Assemble the salad: In a large serving bowl, gently combine the orange slices, prepared red onion, and chopped fresh mint leaves. Pour about half of the dressing over the mixture and toss gently to coat. Add more dressing as needed, ensuring not to overdress the salad.

Finish and serve: Sprinkle the toasted and chopped pistachios over the salad just before serving. This adds a delightful crunch. Serve immediately.