Inspired by a soup from Urth Caffé in L.A. that I was minorly (read: majorly) obessed with when I lived there many years ago, I decided to create one of my own instead of just longing for it from afar. The beauty of the soup is that it was dairy-free; they used potatoes to thicken it instead of heavy cream — which is exactly what I did with this broccoli classic.
To add a little creaminess to my broccoli and cheese soup, I decided to top it with grated Cheddar and, as a classic fat kid move, cut up cubes of cheese and tossed them in the bowl so that one out of every five spoonfuls ended up having a melted, cheesy surprise (my ratio might be off... ). Feel free to do the same, or skip the cheese to make it completely dairy-free.
In a pot, add the potatoes and cover with water. Bring to a boil over high heat, then reduce the heat to medium and cook until potatoes can be easily pierced with a fork, about 40-45 minutes.
Meanwhile, heat the olive oil in a Dutch oven or large pot over high heat until shimmering. Add the onions and a generous pinch of salt, reducing the heat to medium high. When the onions have softened, about 7-8 minutes, add the broccoli stems and the chicken broth. Raise the heat to high and bring the liquid to a boil. Reduce until simmering, then add the broccoli florets and cook until both the stems and florets have softened, about 10-15 minutes more. Seasoning to taste with salt, pepper, and the chile flakes.
When the potatoes have finished cooking, drain them and, working in 2 batches, transfer half of the potatoes and half of the contents of the pot to a food processor and blend until liquified.
Return the contents to the Dutch oven or pot and cook until hot, over medium heat. Ladle the soup into bowls and grate the cheese on top, cutting some of it into cubes and adding them to the bowls, if desired. Top with some fresh dill and serve immediately.