Start the instant pot in Saute mode and heat oil in it. Add diced onions and garlic and sauté for about 3 minutes.
Add cauliflower, cashews, turmeric, cinnamon, broth and salt. Stir it all up. Press Cancel and close lid with vent in sealing position.
Change the instant pot setting to manual or pressure cook mode at high pressure for for 3 mins. After the instant pot beeps, let the pressure release naturally for 10 minutes then release the pressure manually.
Add the lemon juice. Use an immersion blender to blend the soup to a creamy texture. You can also transfer to a blender such as Vitamix to blend the soup. Be careful while blending to avoid hot splatters.
Top with parsley and some chili flakes (optional). Enjoy with toasted bread!