Preheat your oven to the grill setting.
Add the sweet potato to a microwaveable bowl filled halfway with water and pierce the potato with a knife. Microwave for 5 minutes (it will cook further in the oven).
Meanwhile, spread the vegan pesto on the naan. (I like to cook my pizza on a pizza tray or grill tray, to allow the heat to cook it underneath too)
Grate/ finely slice the dairy-free cheese and sprinkle on top. Chop the onion and spinach, and add to the pizza.
Drain and peel the sweet potato then chop into large chunks. Spread them evenly on the pizza. Sprinkle with freshly cracked black pepper.
Bake the pizza under the grill setting for 5 minutes. Keep an eye on it, as it will cook quickly! If you find your pizza is cooking too quickly, you can cover the crust with some tin foil to prevent it burning.
Once golden, remove the pizza from the oven and top with fresh chopped basil, walnuts and flaky sea salt. Slice and enjoy hot!