The reliable pairing of crisp-tender broccoli with a creamy cheese base makes this broccoli cheese soup a traditional American lunchtime classic.
This very simple soup with only few ingredients seems easy at first but involves a subtle complexity to get the textures just right. Some personal experimentation may be necessary to adjust the dish to preference, and the quality of the ingredients becomes paramount with so few actors in this performance.
Key to this soup is the boil to achieve the proper consistency of the final product. All-purpose flour is used as a thickening agent with some fat provided by butter and stock, essentially creating a roux. Starch granules in the flour expand with water as the heat rises, and thicken the result when they burst and spread swollen starch molecules throughout. However, it takes sufficient time for this reaction to occur.
Likewise, a quick blanch in boiling water will break down and soften the tough texture of any vegetable but too long in the bath will reduce the broccoli to a lifeless mush. The two-minute mark is a good compromise and leaves the broccoli still with some crunch, but feel free to add another minute if a more tender texture is desired. This process also assures a bright and vibrant green in the final dish.
Frozen broccoli can be used but is not recommended as freezing does affect the texture; forgo the blanch and add it already thawed at the end. Sharp melting cheeses are best such as Cheddar, Colby, Monterey Jack or Gouda. Avoid hard, fresh or stringy cheeses like provolone, mozzarella, queso fresco, ricotta, feta or Parmigiano-Reggiano.
This meatless dish pairs best as part of a reliable lunch sandwich combo.
Broccoli Cheese Soup
1 lb fresh broccoli
½ yellow onion
¼ c flour
2 T butter
8 oz Cheddar cheese
1 c half-and-half
4 c chicken stock
½ t tarragon
1 Blanch the whole broccoli heads in boiling water for 2 min. Remove and set aside to cool.
2 Dice the onion and grate the carrot. Sauté both in butter and oil until soft, about 5 min. Work in the flour and spices.
3 Slowly add the stock, stirring constantly to incorporate the flour. Bring to a boil, reduce the heat and simmer, covered, for 10 min.
4 Add the half-and-half, then reduce the heat to very low (do not boil after this point). Shred the cheese and add in batches, stirring until completely melted.
5 Roughly chop the broccoli and add just long enough to reheat. Season to taste.