Place a large frying pan over a medium heat, add the oil and butter and once the butter has melted add the zucchini, onions, thyme and salt and pepper. Cook for 20 to 25 minutes, stirring from time to time, until the zucchini and tender and starting to turn golden. Add the garlic and fry for another couple of minutes.
While the zucchini and onions are cooking, rinse the quinoa in several changes of cold water and then place in a saucepan along with plenty of cold water and a pinch of salt. Bring to the boil and then reduce the heat and simmer for 12 minutes or until the quinoa is tender and the long white kernels are coming away from the seeds. Tip into a sieve and leave to drain and steam.
Combine the quinoa and zucchini and onions and toss to mix well. Add the parsley, lemon juice, salt and pepper and stir well. Check the seasoning and adjust as necessary. Serve topped with toasted pine nuts.
You will need to ensure you have a very large frying pan to cook the zucchini and onions so that they cook properly rather than steam. I didn't have pine nuts to hand so substituted slivered almonds, which worked well.