To roast red peppers on the grill, place clean fresh red peppers directly on the grill top. You can also put them directly over the flame on your stove. Turn your peppers frequently, as needed until the skin has turned completely black and starts to blister. When the entire pepper skin has turned black, remove the peppers from the grill and place them into a bowl.
Cover the bowl with a lid or a dish to make it airtight to build up steam. Let the peppers rest in the bowl for 10 minutes. Uncover, remove from the bowl and the skin will slide off easily. Cut the pepper in half to core and remove seeds.
Heat 1 tsp of oil in a large heavy pot over medium-high heat. Add the onions, carrots, garlic, and herbs and saute until the onions are translucent, about 5 minutes. Add the broth, roasted bell peppers, potato and wine. Bring to a simmer over high heat. Decrease the heat to medium-low and cover, simmer until the potatoes are very tender, stirring occasionally, about 30 minutes.
With an immersion hand blender, puree the soup in the pot with the sour cream until it is smooth. Season with salt and pepper to taste. Add the grated parmesan and ladle into bowls.