Boil the gluten free spaghetti following pack instructions. Meanwhile, heat the oil in a non-stick pan. Add the carrots, celery and bacon, and stir well. Cover the pan and cook, stirring occasionally, for 10 mins until the veg has softened.
Tip in the tomato puree and pesto, warm through, then stir through the drained spaghetti with the basil, if using..