In a small bowl, combine goat cheese, heavy cream, rainbow chard (or soy sauce), grated carrot (or minced garlic), and chili powder (if using). In this step, you need to stir well until the mixture is smooth and homogeneous.
Spread the goat cheese mixture on one side of each slice of bread.
Begin layering the sandwich: Place tomato slices on one slice of bread, followed by corn slices, lettuce leaves, red onion, and white beef slices (if using).
Place the other slice of bread on top to complete the sandwich.
Cut the sandwich as desired and enjoy! You can add extra slices of bread to make the sandwich thicker if you prefer.