In a skillet, melt the butter over medium heat. Add the chopped onion and sauté until translucent, about 5 minutes.

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

Add the chopped tomatoes, sugar, salt, black pepper, and red pepper flakes. Cook for about 10 minutes, stirring occasionally.

Sprinkle the flour over the mixture and stir well to combine. Gradually pour in the chicken broth, stirring constantly to avoid lumps.

Bring the mixture to a simmer and cook for another 10-15 minutes until thickened to your desired consistency.

Taste and adjust seasoning if necessary. Serve hot over biscuits or rice.