Cook spaghetti according to the instructions on the packet.
While the spaghetti is cooking, combine the coconut yoghurt, garlic, nutritional yeast, salt and pepper together in a small bowl, and set aside.
Once the spaghetti is done scoop out 1 cup of the water it was cooked in, and drain the rest away. Add the spaghetti back into the pot it was cooked in (without any water). Add the cup of water to the coconut yoghurt sauce and whisk together well. Pour the sauce over the cooked spaghetti and place it over a medium heat. Stir the spaghetti and sauce together and then add the 2 tsp of the tapioca or corn starch and continue to stir until sauce starts to thicken (approx. 3-5mins). Finally stir through the peas (if using) and serve!