Place potatoes, kale carrots, and corn in a microwave-safe mug. Pour in the vegetable broth. Cover mug with microwave-safe plastic wrap and poke a few holes on it with a knife.
Place mug on a plate. With your microwave at medium-high powder, microwave the vegetables for 1 minute 30 seconds. The power output of my microwave is calibrated from numbers 1 to 10, and I set it to 7 for this step. Take mug out of the microwave and stir the vegetables a little. Microwave for another 45 seconds.
Take mug out and let it sit and stir in the pumpkin, soy milk, curry, salt, garlic, and cayenne. Alternatively, you can stir the remaining ingredients in a separate bowl and then pour it into the mug. Cover the mug with plastic wrap again.
With the microwave at a lower power setting (5/10 in my microwave), cook the soup for 1 minute. Take soup out and give everything a stir so that the vegetables cook evenly. Repeat this step 2 more times. Let the soup rest for 2 minutes before eating. This allows the vegetables to finish cooking. Top with cashew cream and chives if you like.