Preheat the oven to 425ºF and line a large baking sheet with parchment paper. Spread the frozen corn (right from the freezer) in a single layer on the baking pan and bake for 20 minutes. After 20 minutes, flip the corn or just stir it around, and bake for another 10 minutes. The corn should just start to brown. Remove from the oven and set aside. Set aside ¼ cup of roasted corn and transfer the rest to the container of a highspeed blender.
Meanwhile, in a large soup pot sauté the onion and celery with a few tablespoon of water for 5 to 7 minutes, adding water as needed, until the onion starts to soften. Now add the garlic, chili powder, cumin, red pepper flakes, and potato and continue to sauté for another minute.
Now add the vegetable broth and bring to a boil. Once boiling, reduce to a simmer and simmer, partially covered for 10 to 15 minutes or until the potatoes are fork tender. Remove from heat.
Add the nutritional yeast, lime juice, tamari, salt, and a pinch of black pepper to the blender with the corn and carefully add the soup as well. Do this in stages if needed.
Blend everything together until completely smooth.
Return the soup to the pot and warm on low heat while you make the salsa. Add all the salsa ingredients to a bowl and mix to combine.