Preheat oven to 350°F (175°C).

Halve butternut squash, remove seeds, and rub flesh with olive oil.

Roast squash cut-side down for approximately 45 minutes, or until fork-tender.

Remove from oven and let cool slightly.

While squash is roasting, dice onion and celery.

Mince garlic cloves.

Heat olive oil in a soup pot over medium heat.

Sauté onion, celery, and garlic until softened.

Add flour and curry powder to the pot and stir to combine.

Season with salt and pepper to taste.

Pour in vegetable broth and stir to prevent lumps.

Bring the mixture to a boil, then reduce heat to a simmer.

Peel, core, and chop apples. Add them to the simmering broth.

Once the roasted squash is cool enough to handle, remove the flesh from the skin using a spoon.

Add the squash flesh to the pot.

Simmer for 15 minutes, or until the apples are soft.

Serve hot, topped with a dollop of yogurt, chopped green onions, cashews, and sliced bananas.