Add the first 4 ingredients to a mason jar, stir then add in the rest. Keep in the fridge.
At lunchtime, take the jar out of the fridge 20 minutes before you want to eat. Heat broth by tipping the broth in a mug and heat in a microwave till boiling (approx. 2–3 minutes) . Pour hot broth into the mason jar, cover and leave for 5 mins.