1. Preheat oven to 325 Farenheit.
2. In skillet, cook veggies in oil until tender-crisp.
3. Stir in flour, then milk; cook and stir until thickened.
4. Remove from heat; add cottage cheese, 2 tablespoons parmesan, salt and pepper.
5. Stuff shells; place in shallow baking dish.
6. Top with remaining parmesan.
7. Bake, covered for 25 minutes.