First, heat the oil/water in a medium-sized pot over medium-high heat.
Meanwhile, roughly chop the onion.
Next, add the onion to the hot oil/water and stir until the onion becomes translucent and the edges become lightly browned; about two minutes.
Then, add the broccoli, spinach, garlic powder, salt and pepper. Stir until the broccoli is hot and steamy, about 3 minutes if your broccoli was fresh or 5 minutes if it was frozen.
Add the water and bring it to a boil. Then, carefully ladle all of the pot's contents into your blender and blend until very smooth.
For the optional buttered toast croutons: pop your bread of choice in the toaster. I usually make about one slice per person. Once toasted, lightly apply non-dairy butter or olive oil (if you like) and cut it into squares.
I usually then take half of the toast croutons and add them to each bowl or cup of soup. The other half stays on the side, giving the option to add extra croutons to the soup or eat them by themselves. You can't lose either way!