Boil the sweet corn kernels in a microwave or on the stove. They can also be steamed in a pressure cooker. Transfer to a grinder jar.
Pulse the boiled kernels to a fine puree. You can add a little water if it looks too dry.
Melt butter in a sauce pan. Add the chopped onion and saute till soft.
Toss in the remaining vegetables and fry till done.
Add 2 cups water and let it come to a boil.
Stir in the sweet corn puree. Let the mix cook for 4-5 minutes on a low to medium flame.
Lastly season the soup with salt and pepper . Stir and cook for another minute. Avoid salt if the soup is for babies under one.
Turn off the flame. Serve warm.