Heat olive oil in large skillet over medium-high heat; stir in the garlic and cook until just beginning to brown. Add the fresh spinach and stir to coat with the oil. Season with red pepper flakes, salt, and ground black pepper. Cover the skillet and cook for 4 to 5 minutes. Pour in a little bit of liquid (water or broth) if your skillet seems dry. As the spinach cooks, it will wilt and reduce in size. Once the spinach is cooked through, add raisins and stir for 1 more minute, until heated through.
