Start by putting the cashew nuts in water, on heat and boil softly so they go soft.
Cut the cauliflower in florets and put it them on a lined baking tray. Add the (unpeeled!) garlic gloves as well and put in the oven. Bake for about 25 minutes.
In the meantime, prepare the penne by boiling for 12 minutes. Drain and set aside.
Chop the onion. Heat some oil in a pan and bake the onion on low heat for about 5 minutes.
Take the cauliflower and garlic from the oven. Peel the garlic and drain the cashew nuts. Add the following to a bowl or a tall measuring cup: cauliflower, garlic, lemon juice, plant milk, nutritional yeast, cashew nuts and salt. Blend until smooth. Note: If you have a great blender you can blend everything at once. If you don't (like a standing mixer), you may want to blend the cashew nuts + plantmilk separately first.
Add the cauliflower sauce the pan with onions, and heat for 2-3 minutes. Mix in the penne and add the chopped parsley.