broccoli-cheese soup

In the true spirit of a comforting, smooth and creamy soup, this broccoli-cheese soup is DELISH. If you've had Panara Bread's broccoli-cheddar, that is my inspiration for this recipe.
 
1/2 medium onion, chopped
5 tablespoons butter, divided
1/4 cup all-purpose flour
2 cups 1% milk (or ff half-&-half)
2 cups chicken broth
8 ounces (1/2 bag) frozen chopped broccoli
1 cup shredded carrots
salt and pepper
8 ounces Velveeta, cubed
1 cup sharp cheddar cheese, grated
Secret Ingredient: 1/4 tsp nutmeg

1. Saute the onion in 1 Tbsp butter until onions are soft. Set aside in small bowl. 
2. Using a wire whisk, heat the remaining 4 Tbsp butter until melted and add the flour in a large pot over medium heat. Cook, stirring frequently, for about 4 minutes.
3. Slowly add the milk; continue stirring with whisk. Add the chicken broth, whisking all the time. Simmer for 20 minutes. (whisk every 2 min or so to prevent burning the bottom.)
4. Add the broccoli, carrots, and sauteed onion. Cook over low heat until the veggies are tender, about 20 minutes.
5. Add salt and pepper to taste.
6. By now the soup should be thickened. Let cool for 3-4 minutes, then pour into a blender and puree.
7. Return the puree to the pot and place over low heat. Add the Velveeta and grated cheddar and stir until well blended and melted. Stir in the nutmeg.

Serves 5. 
I throw in some frozen Pillsbury Buttermilk Biscuits to dip and crumble in the soup. Yummers!