Heat olive oil in a large pan over medium heat. Add sweet potato noodles and fry for about 2 minutes on each side. Add half of the zucchini noodles, toss and fry for about 2 minutes each side. Place the first batch on a plate and fry the rest of the zucchini noodles until cooked through, for about 2 minutes each side. Add the first batch back in, toss, season with salt and pepper and fry for another few minutes.