1 cup sugar
1 tablespoon lemon juice
2 tablespoons unsalted butter
1⁄2 cup chopped toasted walnuts
1⁄2 cup black sesame seeds Flaky sea salt

31⁄2 pounds pumpkin, such as sugar pie pumpkin, cut in half and seeded
4 tablespoons olive oil
1 onion, diced
1 pound sweet potatoes, peeled and diced
2 cloves garlic, peeled
Salt and freshly ground black pepper
Pinch of freshly grated nutmeg
2 tablespoons white or yellow miso
1 quart vegetable stock
1 tablespoon sherry vinegar Crème fraîche (optional)