Preheat your oven to 400 degrees F. Combine the potato, carrot, and yellow onion in a large bowl. Drizzle with olive oil and season with salt and pepper. Spread onto a baking sheet and roast for 30 minutes, until the veggies are easily pierced with a fork. Remove from oven.
Allow the veggies to cool for a few minutes. Add the chicken broth, milk, garlic powder, black pepper, and salt. Whirl on a low setting to combine. Add the roasted veggies slowly to the blender on a low setting. Place the lid on the blender and raise the speed up to medium high until creamy.
Pour into four bowls and top with a sprinkle of red pepper flakes and parmesan.