Heat the oil in a saucepan. Add the squash and sauté for 2-3 minutes over a low to medium heat.
Add the garlic and shallot and cook for a further minute.
Add the stock and chopped tomato to the pan, bring to the boil and reduce the heat to simmer for 8-10 minutes, until the squash is soft.
Remove the pan from the heat and add the blue cheese. Blend with a hand blender and then pass through a sieve into a bowl.
Ladle the soup into serving bowls and serve.