Heat bacon grease in a large pot over medium heat. Stir in the pork, and cook until evenly browned. Remove pork and liquid from the pot, and set aside.
In the large pot, melt the butter over medium heat, and saute the onions until tender and lightly browned. Mix in the flour and paprika, and, stirring constantly, cook until thickened.
Mix pork, green bell pepper, red bell pepper, yellow bell pepper, and jalapeno peppers into the pot. Stir in the beef stock, tomato paste, garlic, salt, and bay leaf. Bring the mixture to a boil. Reduce heat, cover, and simmer 1 to 1 1/2 hours, stirring occasionally.
