Heat the olive oil in a large Dutch oven or pot over medium-high heat. Add the potatoes, celery, shallots, 1/2 teaspoon salt, and pepper to taste and cook, stirring frequently, until the potatoes begin to soften, about 5 minutes. Add the red peppers, sun-dried tomatoes, chicken broth and 1 cup water. Cover and bring to a simmer, then uncover and cook until the potatoes are tender, about 15 minutes.
Transfer the soup and sour cream to a blender and, keeping the lid slightly ajar, puree until smooth. Season with salt and pepper and stir in half of the cilantro. Divide among bowls and sprinkle with the cheese and the remaining cilantro. Serve with the rolls.