Cream of broccoli soup

This is a great weeknight soup. It's quick, it's easy, it's not absurdly high in fat or carbohydrates, and it contains lots of vegetables. It's also satisfying and filling. My two-year-old daughter, who adores broccoli, absolutely loves it. She claps her hands and says "Green! Green!" when she sees it. I know this sounds as if I'm bragging ("My kid positively clamors for broccoli!"), but she really does love it. This recipe is well and truly kid-approved.

Ingredients:
1 large head of broccoli, cut into 1-inch pieces, including the stems
2 cups chicken broth
2 tablespoons butter
1/2 an onion, chopped fine
1 clove garlic, minced
1 tablespoon flour
1/2 cup milk
Cornstarch for thickening (optional)
1/2 cup shredded Parmesan or other strong cheese (this tastes best if you shred it yourself right before adding it, but this recipe will still be fine if you get the pre-shredded kind, or even that stuff that comes out of green canisters in dusty clumps.)
salt
pepper

Bring the broth to a boil in a large pot. Add 1/4 teaspoon salt and the broccoli pieces. Cook until the broccoli is tender, about 7 minutes. Tip the broccoli and broth into the food processor and blend until you have smooth green slime.

Wipe out the pot. Melt the butter in it over medium-high heat, and add the onion and garlic with a few good pinches of salt and grinds of pepper. Saute until the onion is softened and turning transparent but not browning, about 7 minutes. Add the flour and cook, stirring, until no lumps remain.

Now start ladling the broccoli mixture into the pot, little by little, stirring constantly to avoid lumps, until the soup has a pleasantly thickened texture.

If the soup is too thin for your liking, whisk a teaspoon or two of cornstarch into the milk before you add it. (Or just put the milk in without cornstarch if the texture is fine.) Add the Parmesan and stir well. Check the seasonings and serve. You may prefer to have it with toast, grilled cheese sandwiches, or a piece of homemade bread such as whole wheat-yogurt baking powder bread.