How to Make It
In a food processor, puree the fresh and dried chiles with the garlic, ginger, 1/2 cup of cilantro, the vinegar, shallot, paprika and 1/2 cup of the olive oil until smooth. Season with salt and pepper. Reserve 1/2 cup of the piri piri marinade. In a large bowl, rub the chicken pieces all over with the remaining marinade and let stand at room temperature for 30 minutes.
Preheat the oven to 450° with the racks set in the upper and lower thirds. Set a wire rack over a large rimmed baking sheet.
Transfer the chicken to the prepared baking sheet; discard the marinade. Season with salt and pepper and drizzle with 2 tablespoons of the olive oil. On another rimmed baking sheet, toss the potatoes with the remaining 2 tablespoons of olive oil and season with salt and pepper; arrange in a single layer. Roast the chicken on the upper rack of the oven for 20 minutes. Add the potatoes to the bottom rack and roast the chicken and potatoes for 20 to 25 minutes longer, until the chicken is cooked through and the potatoes are golden. Transfer the chicken to a platter and garnish with cilantro sprigs. Serve with the potatoes, lemon wedges, if desired, and the reserved marinade for dipping.