In a large pot, melt the butter over medium heat. Gradually whisk in the flour, stirring continuously until the mixture turns light golden brown, about 5-7 minutes.

Add the diced onion, celery, and bell pepper to the pot with the roux. Stir well and sauté for about 5 minutes until the vegetables are soft and translucent.

Stir in the minced garlic and cook for an additional 2 minutes until fragrant.

Gradually pour in the beef broth while stirring to prevent lumps. Increase heat to bring to a gentle simmer.

Fold in the crab meat, Old Bay seasoning, salt, and pepper. Allow the stew to simmer on low heat for 15-20 minutes.

Taste the stew and adjust seasoning if necessary. Serve hot, garnished with fresh herbs if desired.