Preheat the oven to 230C/450F/Gas 8.
For the pizza dough, place the flour, salt and olive oil into a large bowl and mix well. Add enough warm water to make a soft but not sticky dough.
Turn the dough out onto a lightly floured surface and knead briefly. Roll the dough out to make a circle 0.5cm/¼in thick and place onto a non-stick baking sheet.
For the tomato sauce, place all the sauce ingredients into a bowl, season with salt and freshly ground black pepper and mix well. Spread the sauce evenly over the dough circle, leaving a thin border around the edge.
For the topping, heat the olive oil in a frying pan and cook the butternut squash pieces, garlic and thyme for 5-6 minutes, or until just tender. Season with salt and freshly ground black pepper, then sprinkle the topping over the pizza base.
Transfer the pizza to the oven and bake for 10-12 minutes, or until the base is crisp and cooked through.
To serve, place the pizza onto a serving plate.