Cook pearl barley in water, bringing to a boil. Cover and lower to simmer and cook about 1 hour. Remove from heat and set aside.
Start the roux in a large soup pan or dutch oven by combining butter and flour. Cook over low heat, stirring continually with a wood spoon, about 30 - 45 minutes.
Chop the onion, bell peppers, carrots, celery and garlic.
Cook the chopped vegetables in butter in another pan over medium heat, stirring often until softened and onions just start to brown. Mix in smoked paprika, salt, pepper and brown sugar. Remove from heat and set aside.
Continue to cook the roux until it becomes dark brown, like chocolate. Roux should be smooth and should not be sticking to the pan. It's a good idea to taste the roux to make sure it isn't burned. If it is burned, you need to start over.
Stir vegetables into roux.
Mix water with beef base until mixed well.
Stir into vegetable mixture and bring to a low boil. Cook until mixture is heated through and starts to thicken, about 20 minutes.
Add barley and okra.
Mix in smoked sausage and lower to simmer for about 10 minutes.
Add chili flakes and serve immediately.