Start by making the roux with butter and brown rice flour.
In a skillet over low-medium heat, melt butter.
Once butter is melted, whisk in the brown rice flour.
Make sure to keep the mixture moving.
Cook for about 5 minutes whisking constantly.
Next, add in milk slowing and whisking into the mixture. This should take another 5 minutes to combine all of it.
Take of the roux off the heat and set aside.
Over high heat, add the frozen or fresh broccoli florets to a large pot.
Add 5 Cups of chicken broth on top of the broccoli.
Let boil and cook for 10 minutes if broccoli is frozen and cooked already and then lower to simmer. 15 minutes if broccoli is fresh.
Then, slowly add in the roux. You want to get the soup to a thickness you are comfortable with. I used all of it and it was extremely thick. It's your call how thick you want it.