Preheat oven to 400° F. Peel the squash with a vegetable peeler. (I have a serrated one that works really well for tough-skinned things like winter squash.) Cut the squash in half with a sharp knife, and then, using a spoon, scoop out the seeds and fibrous strands. Cube the peeled squash into 1-inch pieces and place in a large mixing bowl.
Peel the onion, and cut off both ends. Cut the onion in quarters, and pull sections apart like petals. Add the sliced onion to the squash, then drizzle with the olive oil, stirring until vegetables are well coated. You want to use just enough oil to coat, but not so much that the vegetable chunks are drowning and the oil is pooling in the bottom of the bowl. Add the Herbes De Provence, and salt and pepper to taste, tossing so that the seasonings are distributed throughout.
Spread the seasoned vegetable mixture on a rimmed baking sheet in a single layer. Don’t over-crowd the sheet as this will cause your squash to be soft on the outside. Bake in the oven for 20 to 30 minutes, until the edges of the squash to start to brown. The onions may brown and crisp more quickly – this is ok, browned onions are still tasty. When the squash is done, remove baking sheet from the oven, and then transfer vegetables to a serving bowl. Serve immediately.
If I have leftovers, I put them in a blender with some chicken stock and puree the vegetables into a hearty winter soup. I add just a touch of cream after warming it for an extra rich flavor. Drizzle surface of the soup with some pumpkin seed oil or walnut oil.