Preheat the oven to 160 °C. Prepare the marinade: in a salad bowl, mix the barbecue sauce, the tomato pulp and the balsamic vinegar. Season with salt and pepper.
Cut one and a half onions into thick strips. Place the turkey leg in an ovenproof casserole dish with a little olive oil. Arrange the tomato mixture and the onions on top. Cover the casserole with the lid and bake for 2.5 hours.
Using a peeler or mandoline, cut thin strips of carrots and courgette. Cut the spring onions into thin slices.
Scrape the meat off the turkey leg with a fork.
Cut the baguettes in half and slice each half lengthwise. Arrange a generous amount of shredded turkey on the baguettes, and top with a few spinach shoots, vegetable strips, the remaining red onions and finally the spring onion.
