Mince the onion and garlic and fry in 3 Tbsp of butter, in a large pot, over low heat for 10 minutes.
Wash, chop, then add the broccoli to the pot. Let fry on low for another 10 minutes.
Add the chicken stock and water, then let simmer for ½ an hour.
In a small pot melt 3 Tbsp of butter over medium heat. Then add the flour and stir into a paste. Let brown for 1 minute, then slowly stir in the milk. Stir constantly until it begins to boil. Then add to the main soup pot.
Stir well, then add the cheese and heavy cream. Add salt and pepper to taste.
Let simmer on low for ½ hour.
Recipe by Officially Gluten Free at https://www.officiallyglutenfree.com/gluten-free-broccoli-cheddar-soup/