Butternut Squash Pesto Pizza/Flatbread without juice

1 1/4 kg butternut squash or 1 1/4 kg kabocha squash or 1 1/4 kg pumpkin sunflower oil 20 g butter (the original recipe calls for 40) 1 medium onion , chopped[...]

2 1/2 cups butternut squash, peeled and diced 1/2 cup chopped onion (about 1 small) 1 tablespoon brown sugar , packed 1 teaspoon sea salt or 1 teaspoon kosher[...]