Preheat the oven to 180°C. Mix the soy, honey, garlic and five spice in a lidded jar and shake well. Grill the pumpkin seeds, tossed in a little oil, under the griller or in the oven, until they pop. Place the chicken breasts in the bottom of a baking tray or casserole dish and pour over marinade (you can leave it to marinate for a couple of hours if you have time).
Place the chicken in the oven and cook for about 20 minutes. Turn once or twice during cooking.
Serve on bed of rice, drizzle with the juices, sprinkle with the popped pumpkin seeds, and have with a fresh, crispy garden salad.