1. Preheat oven to 350ºF (180°C). Heat oil in a large skillet set over medium-high heat; cook green pepper, red pepper, green onions, garlic and salt for 3 to 5 minutes or until vegetables are slightly softened. Let cool.
2. Using an electric mixer, beat cream cheese, mozzarella, Swiss, Cheddar, sour cream, mayonnaise and Cajun seasoning; fold in pepper mixture and cooked shrimp.
3. Bake for 15 to 20 minutes or until all cheese is melted. Stir and serve with a toasted baguette for dipping.