Heat a large stock pot or Dutch-oven over medium-high heat with vegan butter. Once butter is sizzling add celery, carrot, shallot, and leek and sauté for about 3 to 4 minutes. Add dried thyme and stir to combine, sautéing another 2 to 3 minutes, until onions and leeks are softer and translucent. Lower heat slightly, if needed, to prevent burning. Stir in corn and cook 2 to 3 minutes, only stirring once. Add all the blended broth and fresh sage, and bring to a low simmer. Once mostly heated through add kale, and let it wilt for 2 minutes. Serve immediately and garnish each serving with croutons, vegan parmesan, and ground black to pepper, to taste.