Optional: if making your own dough, do this first as it needs about 1 hour to rise.
Preheat oven to 400°F or 200°C.
Add butternut, onion, and garlic to an oven dish or baking sheet, drizzle with cooking oil and add a pinch of sea salt and black pepper. Toss to coat. Roast for 20-30 minutes or until butternut/pumpkin is soft.
Meanwhile, heat cooking oil over high heat in a pan. Cook chicken pieces until slightly browned.
Season with salt and pepper. When ready, transfer to a bowl or plate.
In the same pan, add some extra cooking oil and saute onions for 2-3 minutes while stirring. Then add and spinach and cook until just wilted. Set aside.
When butternut is soft, take out the garlic and push the inside of the roasted garlic out of the skin. Add with all other sauce ingredients in a blender and process until smooth. Add water if needed to improve the consistency of the sauce. Season with pepper and salt.
Roll out dough, top with sauce, spinach mix and chicken pieces. Sprinkle dried oregano on top.
Cook in the oven for about 15 minutes or until crisp.
Optional: add a little bit grated Parmesan (or other cheese) on top.