Preheat oven to 375 F. Lightly grease a 2 quart baking dish, 8X8 baking dish, or 10 inch cast iron skillet.
Heat the oil in a large skillet over medium heat. Add the onions, red pepper, and corn, and saute 4 minutes until translucent. Add the garlic and chilis and saute one additional minute until fragrant. Add the cumin, coriander, smoked paprika, and scallions, toss with vegetables to coat with spices. Remove from the heat, set aside.
To make the batter add cornmeal, flour, salt, cornstarch, sugar, baking powder, and sea salt to a bowl and whisk to combine.
In a small bowl, whisk together the sour cream and melted butter.
Add the sauteed vegetable mixture and ¾ cup vegan cheese to the dry ingredients and stir to combine. Add the sour cream and butter mixture and stir with a spatula to combine. Transfer to prepared baking vessel and sprinkle the remaining cheese over the top.
Bake uncovered, for 25-35 minutes until golden.
Sprinkle with scallions and serve warm.