1. 1. Preheat the oven to 375°F (190°C).

2. 2. Cook the spaghetti according to package instructions until al dente. Drain and set aside.

3. 3. In a large bowl, mix together cooked chicken meat, great northern beans, corn, green peas, and cooked instant rice.

4. 4. Add in diced spring onions, yellow onion, and dijon mustard. Mix well to combine all ingredients.

5. 5. Stir in marinara sauce and chicken stock until everything is evenly coated.

6. 6. Pour the mixture into a greased casserole dish.

7. 7. Top the casserole with a layer of bread crumbs and herb seasoned stuffing mix.

8. 8. Drizzle ranch dressing over the stuffing layer for added flavor.

9. 9. Cover the casserole dish with foil and bake in the preheated oven for 25-30 minutes, or until heated through and bubbly.

10. 10. Remove the foil and bake for an additional 10 minutes to crisp up the topping.

11. 11. Serve hot and enjoy!