Whisk the egg white in a bowl and tip the Parmesan onto a plate. Dip each chicken breast into the egg and then lightly press each side down on the Parmesan, so that it is thoroughly coated.
Place onto a grill pan lined with foil and grill for 10-15 mins, until the crumbs are nicely golden and the chicken is properly cooked through, with no pink showing (this will depend on the size of the chicken breasts).
In the meantime, while the chicken is grilling, cook the potatoes in boiling salted water for 10 mins, adding the sugar snaps for the last 2 mins. Mix the vinegar, mustard and oil in a large bowl.
Drain the potatoes and sugar snaps, tip into the bowl of dressing, toss together and season. Allow to cool slightly, then stir through the rocket. Divide between 4 plates and serve with the chicken.
*Products are subject to availability in selected stores.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.