This broccoli cheese soup is packed with broccoli flavor and is extra cheesy. It is made without flour and butter and gets its thick, creamy base from a potato! When shopping for this soup, look for broccoli sold with long stalks. We chop the stalks up and cook them with the potato. After a quick blend, the stalks and potato turn into a delicious, creamy soup. If you can only find broccoli heads or florets, you can still make the soup. See our tips in the article.
1 large onion, finely chopped
4 medium garlic cloves, peeled and smashed
2 tablespoons unsalted butter or olive oil
2 pounds broccoli with stalks
3/4 teaspoon fine sea salt, plus more to taste
1/2 teaspoon fresh ground black pepper
1/8 to 1/4 teaspoon crushed red pepper flakes, omit if sensitive to spice
1 teaspoon Dijon mustard
1 medium-to-large potato, peeled and chopped
1 bay leaf
4 cups water or broth
1/2 cup half and half, optional
8 ounces sharp cheddar cheese, grated, about 2 cups
Thinly sliced chives, for serving, optional
Fish sauce, optional, see notes
Slice the florets from the stalks. Set the broccoli stalks aside and cut the florets into small bite-size pieces (watch our video for reference). Throw the florets into a bowl and set them aside for later.
Grab the broccoli stalks and cut about 1-inch from the bottom of each stalk and discard it. Use a vegetable peeler to peel away the tough outer layer of the stalks, and then slice the stalks into 1/2-inch pieces.
Melt the butter in a large pot like a Dutch oven over medium heat. When it has melted, toss in the onion and garlic cloves. Cook, occasionally stirring until the onions are soft and smell sweet; about 5 minutes.
Add the chopped broccoli stalks, potato, 3/4 teaspoon fine sea salt, 1/2 teaspoon freshly ground black pepper, Dijon mustard, and red pepper flakes (if using). Cook for two minutes, and then add the bay leaf and four cups of water. Bring the soup to a boil, and then reduce to a low simmer. Cook, at a low simmer, until the broccoli and potatoes are tender, about 15 minutes.
Stir in about half of the broccoli florets to the soup, cover with a lid, and cook until they turn bright green and are tender, 3 to 5 minutes. Adding the florets in this step makes sure that our soup stays green.
Turn off the heat, remove the bay leaf, and then use an immersion blender to blend the soup until smooth. You can also use a blender, but be careful to blend the soup in batches, do not fill more than halfway, and hold the lid down firmly as you blend. Hot liquids can cause steam to build in the blender, and the top can pop off.
Place the pot back onto the burner and heat over medium heat. Stir in the remaining broccoli florets, cover the pot again, and cook until they turn bright green and are tender, 3 to 5 minutes.
Stir in the half-and-half and cheese. When the cheese melts into the soup, taste and then adjust with additional salt and pepper to taste. For a pop of flavor, add a few dashes of fish sauce. Serve with chives scattered on top.