Method
Preheat oven to 400°
Line baking sheet with parchment paper and set beside cutting board
Add butternut squash to baking sheet
Peel and slice parsnips and add to sheet
Peel celery root with a small knife and cube. Add to sheet
Core and peels apples, add to sheet
Remove leaves from tarragon sprig and place on top of vegetables
Toss mixture with a little olive oil and season with salt and pepper to taste (I generously used kosher salt and pepper)
Roast at 400° for 40 minutes
Carefully remove tray from oven and set aside to cool slightly
In a large stock pot, pour in low sodium chicken broth and add two tablespoons of butter
Carefully add the vegetable mixture and bring to a gentle boil on medium heat
Lower heat to low and simmer for 20 minutes
Add 2 cups of heavy cream and blend thoroughly with immersion blender
I allotted up to a tablespoon of apple cider vinegar, but add teaspoon by teaspoon until you reach your desired taste (mine was 2 1/2 teaspoons)
Garnish with sprig of tarragon and serve