Preheat oven to 180ºC/350ºC
Pour quinoa into a sieve and rinse well under running water. Add water to a pot and bring to the boil, then add the quinoa. When it starts bubbling, cover with a lid and simmer for 10 minutes until the quinoa has soaked up all of the liquid and the quinoa is light and fluffy. Drain any excess water away.
Heat the oil in a pan and add the onion and garlic, and fry until fragrant. Pour in the frozen peas and stir until they start to soften, then using a masher, squash the peas to break them up. Add in the spinach leaves and fresh thyme then stir and remove from the heat.
Whisk the egg into a bowl, then add all of the remaining ingredients into the bowl and stir well.
Using a tablespoon size (roughly), form the mixture into little balls. Place onto a baking tray lined with parchment.
Bake in the oven for 20 minutes until golden. Leave to cool fully before serving.