Prepare pasta according to package directions.
While pasta is cooking, sauté beef in a large skillet until browned; drain well. Add taco seasoning mix and water; simmer 5 minutes or until thickened. Stir in beans and cheese. Cook until smooth and well mixed.
When pasta is done, drain well.
Fill shells with beef mixture (1-2 tablespoons per shell).
Combine picante sauce and tomato sauce in a saucepan. Cook until heated, stirring occasionally.
Preheat oven to 350° F.
Spread 1/2 cup sauce over the bottom of a 9 x 13-inch greased baking pan. Place filled shells side by side on top of sauce; pour remaining sauce evenly over shells. Sprinkle with olives. Cover with aluminum foil; bake 35 to 40 minutes or until thoroughly heated.
Sprinkle with green onions. Cover and let stand 5 minutes before serving.
Please Note: Nutritional values listed may vary from final results depending on actual measurements and brands used to prepare the recipe.