Preheat the oven to 400°F (200°C). Prepare the squash for roasting.

Cut the acorn squash in half, scoop out seeds, and coat with olive oil, salt, and pepper. Place cut side down on a baking sheet and roast for 30-40 minutes.

In a large Dutch oven, heat olive oil over medium heat, add onions, carrots, and celery. Sauté for 5-7 minutes until softened.

Stir in minced garlic and cook for 1 minute until fragrant.

Add vegetable stock and roasted squash flesh to the pot along with sage, thyme, and rosemary. Simmer for 10 minutes.

Puree the soup with an immersion blender until smooth, then stir in half and half cream.

Serve hot, garnishing with optional toppings like honey, red pepper powder, or cinnamon.