Reserve 3 tablespoon mojo for the potatoes.
In a large zip top bag or shallow dish, marinate chicken for 15-30 minutes up to 4 hours.
Preheat oven to 400 degrees F.
In a large bowl or large zip top bag, whisk together the reserved mojo, olive oil, garlic powder, red pepper flakes, 2 teaspoon salt and 2 tablespoon pepper. Add potatoes and toss around to coat well.
Put potatoes onto a baking sheet, along with marinated chicken. Season the chicken with the remaining 2 teaspoon salt and 2 teaspoon pepper, then pour the oil and mojo mixture from the bowl used with the potatoes over the chicken and potatoes on the baking sheet.
Bake in oven for 45-50 minutes, or until chicken is cooked through (chicken is done at 165 degrees F).
Serve immediately, with chimichurri sauce.