Method
Heat the oven to 425°F (220°C) and line a large rimmed baking sheet with parchment paper.
Toss the pumpkin, onion, carrot and garlic with the olive oil, salt, pepper and cumin, then spread everything in a single layer.
Roast 30 to 35 minutes, stirring once halfway, until the pumpkin is tender and the edges are browned.
Scrape the roasted vegetables into a large pot, add the broth and bring to a simmer over medium heat. Simmer 10 minutes.
Blend until silky with an immersion blender, or in batches in a blender filled no more than halfway, lid vented and covered with a towel.
Stir in the cream and lemon juice and warm through over low heat without boiling. Taste and add more salt if needed.
Ladle into bowls and top with roasted pumpkin seeds, a swirl of cream or crispy sage leaves.