Preheat the oven to 200C/400F.
Slice the spaghetti in half. Scoop out the seeds and discard. Drizzle the olive oil over the spaghetti squash and sprinkle the salt and pepper all over. Place over an oven tray lined with parchment paper and bake in the oven for 45 minutes. Take out of the oven and let it rest for a few minutes before using a fork and scooping the spaghetti off its shell.
Slice the onion, peppers and mushrooms. Mince the garlic. Shred the turkey breast. Dice the tomato and avocado. Chop the cilantro.
Heat the olive oil in a frying pan and add the garlic and onions. Cook for a minute and add the peppers. Cook for a couple of minutes until wilted. Add the mushrooms, shredded turkey, taco spice and water. Cook another minute or two until the water has simmered down. Turn off the heat.
Add the taco meat over both halves of the spaghetti squash, top with the tomatoes, avocado, olives and cilantro!