Classic Butternut Squash Soup Recipe

Name: Classic Butternut Squash Soup Recipe
Ingredients: 1 (2 1/2 pound/1kg) butternut squash, peeled, seeded, and cut into 1-inch cubes; 1 large (8-ounce; 215g) carrot, peeled and cut into 1-inch chunks; 2 tablespoons (30ml) extra-virgin olive oil; 7 tablespoons (100g) unsalted butter, divided (see note above); 1 large (8-ounce; 215g) yellow onion, thinly sliced; 4 medium cloves garlic, thinly sliced; 4 cups (1l) homemade or store-bought low-sodium chicken or vegetable stock, plus more as needed; 2 sprigs fresh thyme; 1 bay leaf; Kosher salt and freshly ground black pepper; 3/4 cup (180ml) heavy whipping cream; 1/4 cup (60ml) sour cream; Pinch ground cinnamon; Pinch nutmeg; 20 fresh sage leaves (optional, see note above)