Preheat your oven to 400°F (200°C).

Cut your celery into thirds and place it on a baking sheet. Drizzle with 1 tablespoon of olive oil, then season lightly with salt and pepper. Roast for 30 minutes.

In a pot, heat the remaining tablespoon of olive oil over medium heat and sauté sliced cremini mushrooms for 8-10 minutes.

Add diced Yukon Gold potatoes to the pot, season with salt, pepper, and dried thyme, and cook for another minute.

Pour in enough water or vegetable stock to cover the potatoes and bring to a boil. Simmer for about 20 minutes.

Remove half of the potatoes, blend the roasted celery with remaining soup liquid until smooth, then return reserved potatoes to the pot.

Bring the soup back to a gentle boil, add elbow pasta and cook according to package instructions.

Serve in bowls garnished with fresh dill, paprika, or red pepper flakes.