Preheat oven to 400 degrees Fahrenheit.

Peel and cut orange beet, red beet, parsnip, carrot, sweet potato, Yukon gold potato, and acorn squash into bite-sized cubes.

Toss the cubed vegetables with fresh rosemary and olive oil.

Spread the vegetables on a large baking sheet.

Roast in the preheated oven for 20-25 minutes, or until slightly tender.

While the vegetables are roasting, heat olive oil in a soup pot.

Add chopped leeks, garlic, and celery to the pot and sauté until slightly tender.

Add the roasted vegetables to the pot.

Pour in 3/4 cup of apple cider (or enough to almost cover the vegetables).

Simmer for 10-15 minutes.

Add vegetable stock and simmer for another 15-20 minutes, or until all vegetables are tender.

Adjust the amount of vegetable stock to achieve the desired thickness.

Ladle the stew into bowls.

Sprinkle with chopped pistachios before serving.