Season the chicken and cover with the mustard. Place in a small roasting tin and bake for 25-30 mins. Remove from the oven.
Break the bread into small chunks and scatter over a baking tray. Drizzle the oil over the bread and season. Bake in the oven for 10 mins until toasted.
Whisk the orange juice in a small jug with the vinegar, mustard and a touch of seasoning until smooth. Stir in the oil.
Place the pomegranate on a plastic plate or a wide plastic bowl and bash the skin with a rolling pin to force out as many of the seeds as possible. Turn the skin inside out to reach the remaining seeds stuck inside and tease out with a fork. Remove any bits of pith that have landed in the plate. Transfer the seeds to a large bowl and pour the juice into the dressing mixture. Place the salad leaves and orange segments into the bowl with the pomegranate seeds and lightly toss. Divide onto 2 dishes.
Thinly slice the chicken and lay out over the salad. Dash over with the dressing and then serve with the toasted croutons scattered on top.
Store any excess dressing in a small container and keep refrigerated. If the oil sets just let the dressing warm up to room temperature and shake well.