Cover the sunflower seeds with a couple inches of boiling water, cover and let soak for 1 hour.
Heat oil in a large pot over medium heat. When shimmering, add the onion and a big pinch of salt. Sauté until translucent, about 5 minutes. Add the corn, celery, thyme and garlic, cook for another 2-3 minutes, until softened.
Add the potato and 3 cups of stock. Bring to a boil, cover and cook for 5-10 minutes until the potatoes are very tender.
Transfer half the mixture to a high speed blender along with the sunflower seeds (drained), miso, nutritional yeast and maple syrup then blend until smooth. Return to the pot and heat for another couple minutes, until warmed through. If the soup seems too thick, add more stock.
Remove from the heat and stir in the apple cider vinegar. Taste for salt and add more as needed. Serve warm with shiitake bacon and basil.
For the Shiitake Bacon
Preheat the oven to 400 F
Heat oil in large, oven safe skillet. Add the mushrooms, soy sauce, maple syrup and smoked paprika. Sauté over medium high heat for 3-5 minutes, until the mushrooms have softened.
Bake for 15-20 minutes or until brown and crispy. Let cool slightly before serving.