Preheat the oven to 375°F. 

Add potatoes to a saucepan and with water. Cover and bring pan to a boil. Cook until potatoes are tender when poked with a fork, approximately 12-15 minutes. 

Drain the water and leave potatoes in the saucepan. Cover and allow to steam for a few additional minutes. 

Mast potatoes lightly with a potato masher. Add butter, sour cream, milk, parmesan cheese, salt, and pepper and stir until smooth. Put aside. 

In a large oven safe skillet with walls, mix the ground beef and sausage. Season meat with salt and pepper. 

Cook meat over medium heat until browned, making sure to break up the meat into small pieces with a wooden spoon. Drain some of the grease (leave some in the skillet) and move meat onto a plate. 

Into the skillet, add onion, celery, and carrots. Sauté for 5-8 minutes or until tender. Add garlic and flour, combine. Cook for 1 minute.

Add broth, bouillon cube, tomato paste, Worcestershire sauce, herbs, and bay leaves. Stir to combine.

Bring to a simmer and cook for 5 minutes. Add extra seasoning if needed. Remove bay leaves from the mixture and add frozen peas, corn, and the meat from the plate. 

Smooth the mixture over the bottom of the skillet. Spoon the mashed potatoes on top of the mixture until it is completely covered. Sprinkle with cheddar cheese.

Bake for 30 minutes or until top is golden and bubbling. 

Allow to cool for 15 minutes before serving.