In a large pot, add vegetable oil and heat to medium heat. Add chopped white onion and saute for about 1 1/2 minutes. Sprinkle 1/4 teaspoon on the onions. Then add garlic, and saute until the onions are translucent.
Remove onions and garlic from pan, and set aside.
Saute breakfast sausage, and cook until no longer pink. Drain grease.
Add smoked sausage and allow it to brown, saute for two or three minutes.
Add barbecue sauce, tomato sauce, brown sugar, mustard powder to the pot. Add at beans and simmer on low for about 45 minutes before serving.