Step 1 Peel and halve the potatoes and place in a pot filled with water. Simmer until fork tender, about 30 minutes. Drain and set aside.
Step 2 While the potatoes are cooking, roast the chiles: Place the chiles over high heat on a rack over a stove-top burner. When the skin is charred all over, place the peppers in a paper bag. Set the peppers aside for about 10 minutes to cool, then remove and peel the skin — do not rinse. Discard the stems and seeds, and dice the peppers into one-eighth-inch squares; you should have about 2 cups. Set aside.
Step 3In a heavy-bottomed pot, heat the olive oil over medium-high heat. Add the onions and cook, stirring frequently, until tender, 6 to 8 minutes. Add the garlic and cook until aromatic, about 1 minute. Stir in the white wine, scraping any flavoring from the bottom of the pan.
Step 4Stir in the cream, water and potatoes, and bring to a low simmer, then remove from heat. Purée the soup using an immersion blender or in batches using a stand blender.
Step 5Stir in the diced chiles, and season with 2 teaspoons salt and 1 teaspoon pepper, or to taste. Thin the soup, if desired, with cream or water. Hold in a warm place.
Step 6To prepare the garnish, heat a small pot of oil to 350 degrees. Deep-fry the leek, bell pepper and chile until brightly colored and lightly crisp, about 30 seconds. Drain.
Step 7Plate the soup, topping each serving with the fried garnish.