Butternut Squash With Pistou with parmesan

2 1/2 pounds butternut squash 2 tablespoons butter 2 tablespoons olive oil or canola oil 4 cloves garlic minced, normal size, or 2 large cloves, or to taste 4[...]

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[...]