Given broccoli’s top billing, you might think that the soup would be full of this nutrient-rich vegetable, but most of the time you can barely detect its presence.
We wanted a recipe in which the cheese enhanced rather than camouflaged one of our favorite vegetables.
Our research revealed an unexpected technique to coax flavor out of the broccoli: Cook the ever-living daylights out of it. We briefly sautéed chopped florets and stems in a little butter, added some water, and let it simmer, covered, until it was super-overcooked. When we incorporated it into our soup, its bitterness was gone and its flavor stood up nicely against the rich, sharp cheese.
But it wasn’t perfect: Now the soup had an unappealing gray hue, and suddenly we needed to mind the pot for as long as it took to cook. To combat the latter problem, we added baking soda to the cooking water, which sped up the cooking. Now, in much less time, the broccoli was fully softened, sweet, and nutty. And to brighten the soup’s color, we added some fresh baby spinach right before we pureed the soup. This gave the soup a vibrant green color and also enhanced the vegetable flavor.
As for the cheese, we found that incorporating cheddar, along with some Parmesan, gave the soup enough cheesy flavor without making it heavy.