Mix the sour cream and salsa sauce. Set the mixed sauce aside. Heat the oil in a skillet over medium heat. Add the green pepper and chopped basil; saute for 8-10 minutes, stirring occasionally. Add the olives, refried beans and mixed sauce. Cook uncovered for 3 minutes.
Preheat the oven to 370 degrees F. Coat the bottom and sides of a baking dish with oil. Pour the bean mixture into the baking dish. Sprinkle with mozzarella cheese.
Place on the middle rack of the oven and bake until cheese melts and top is lightly golden brown.
Serve with bread or tortilla chips.