Drain and rinse the jackfruit and cut each piece in to thin slices from the longest point of the triangle. Put the sliced jackfruit in a bowl with the tamari, white pepper and nutritional yeast and stir to combine. Set aside.
Add the olive oil to a large soup pot or saucepan and heat over low heat. Add the garlic, onion, celery, carrot, bay leaves and thyme and sauté for 5 minutes. Add 2 tablespoons of water and cook, covered, for around 5 minutes or until the vegetables have softened.
Add the jackfruit and sauté for 3 minutes pulling it apart gently with a fork as you cook.
Add the 1L of stock + the 2 cups of water and bring the soup up to a boil. Reduce the heat and simmer for 20 minutes.
Add the lemon zest and the broken spaghetti, cooking for another 7 minutes or until just al dente - the spaghetti will continue cooking in the hot soup after you take it off the hob.
Remove the bay leaves and thyme, stir in the baby spinach and season with salt (a good pinch should do it) to serve.