Preheat your oven to 400°F (200°C).

Trim the root ends from the celery and cut the stalks into thirds. Toss with olive oil, salt, and pepper, then roast for 30 minutes.

Heat remaining olive oil in a large pot over medium heat. Sauté diced mushrooms for 8-10 minutes until browned.

Add diced Yukon gold potatoes, season with salt and pepper, stir and cook for 5 minutes.

Pour in water or vegetable stock and add thyme. Bring to boil, then reduce to simmer for 20 minutes.

Blend half of the soup mixture with roasted celery until smooth, then return to pot.

Bring the soup to a gentle boil, add elbow pasta and cook per package instructions, usually 8-10 minutes.

Serve hot and garnish with optional toppings as desired.