In small saucepan, combine flour and oil; mix well. Cook, stirring constantly, over medium-high heat for 5 minutes. Reduce heat to medium; cook, stirring constantly, about 10 minutes or until mixture turns reddish brown, then pour into your slow cooker.
Stir in all remaining ingredients into your slow cooker except the shrimp and rice. Cover and cook on Low setting for 7-9 hours. About 20-30 before serving, add cooked shrimp to gumbo mixture in your slow cooker and mix well. Cover and cook on Low setting for an additional 20 minutes.
Serve over rice, enjoy.
Notes
Figure about 50 Baht for good smoked sausage, for the shrimp, through Tesco, Whites will cost about 100 Baht for 340 grams. For 6 servings, this is about 74 cents per serving.