Preheat an oven to 400°F. Place chickpeas on a rimmed baking sheet, and toss with olive oil, rosemary and couple pinches of red chile flakes and salt. Roast, tossing occasionally, until crispy and golden on the outside and creamy within (about 20 - 25 minutes). Season to taste with additional salt and finish with a sprinkling of chopped rosemary.