Cook the puy lentils and pearl barley in separate pots of boiling water until tender, about 20-30 minutes.

Drain and rinse both the lentils and barley in a colander.

In a mixing bowl, combine the cooked lentils, barley, and orange segments.

Prepare the dressing by whisking together olive oil, red wine vinegar, Dijon mustard, salt, and pepper.

Pour the dressing over the salad and toss gently to combine.

Slice the hard-boiled eggs and place on top of the salad before serving.