Alkmaarse kaassoep (Alkmaar cheese soup)

From our Sinterklaas Avond dinner last night. To stick with tradition, and the ethnic traditional, we serve a meal of Dutch foods, which it turns out aren't bad, just boring: Alkmaarse kassoep (cheese soup), Huzarensalade (Hussar's salad), Gestoofde Runderlappen (Dutch stewed/spiced beef), Boerenkool met aardappel (kale and potatoes), and Windmill cookies (which I have yet to make, but there's a recipe on epicurious) to finish things off. The soup is my favorite.

Alkmaarse kaassoep (Alkmaar cheese soup)

Origin: Classic Dutch Cooking
Yield: serves 4
Cooking Time: 30 minutes
Ethnicity: Dutch

Ingredients:
  ● 3 tbsp butter
  ● 1 onion, chopped
  ● 1/2 cup flour
  ● 5 cups milk
  ● 1-1/4 cups mature (sharp) Gouda
  ● 1 small celeriac
  ● salt
  ● toast (croutons)

Directions:
1. Melt the butter in a pan. Add the onion and cook over low heat, stirring occasionally, for 5 minutes or until softened.
2. Stir in the flour and cook, stirring constantly, for 2 minutes, then gradually stir in the milk.
3. Continue to cook, stirring, until slightly thickened. Add 1/2 cup of the grated Gouda and cook, stirring occasionally, for about 15 minutes.  Meanwhile, peel and finely dice the celeriac, then cook in a pan of boiling water, for about 10 minutes, until softened.
4. Drain the celeriac and add to the soup with the remaining cheese.
5. Season to taste with salt, ladle into warm soup bowls and garnish with chives. Serve immediately with toast or croutons.

Some variations I've seen online:
• Add more cheese, less milk
• Color with powdered saffron, thicken with pureed potatoes, flavor with 1/2 tsp crushed caraway seeds.
• Top the soup with a cheese crust made from a mixture of three crushed rusks, 1-3/4 cups grated Gouda and a pinch of milk paprika sprinkled over top. The pan should then be placed under a preheated broiler until the crust is a golden brown.