Begin by making the dressing. Add all of the ingredients to a food processor and process until smooth.
Place the quinoa in a fine mesh sieve and rinse well under running water. Place in a saucepan along with the water and bring to a boil. Cover and reduce the heat to its lowest setting and cook for 12 minutes. Turn the heat off and leave covered for 10 minutes before fluffing with a fork. Place in a bowl and refrigerate until chilled.
Toss the walnuts in frying pan and place over a low heat. Shake the pan every now and again toast for 5 minutes or until they smell toasty. Leave to cool.
Add the remaining salad ingredients, with the exception of the nuts, to the chilled quinoa and toss to combine. Place in a serving bowl. Scatter the walnuts on top and drizzle with the dressing and toss just before serving.
For a vegan option, substitute agave syrup for the honey.