Peel potatoes if you have to (I don’t!), chop into 2″ chunks. Boil in a large pot of water until tender.
While potatoes are boiling, combine oil, ground pork, ground beef, grated veggies, and garlic in a large pan. Cook on medium high heat, stirring and breaking up meat chunks frequently.
Once meat is cooked through and veggies are tender, whisk together chicken broth and corn starch until smooth.
Pour over meat and veg mixture, season with pepper, salt, rosemary, savory, and parsley. Stir until well combined and broth mixture starts to thicken. Remove from heat.
Once potatoes are tender, drain and transfer to a large bowl – I like to use my stand mixer. Mash/whip for 30 seconds or so, until potatoes have broken down a bit. .
Add butter, chicken broth, and sour cream, continue to beat until smooth. Season with salt and pepper
Preheat broiler to high.
Transfer meat mixture to pan(s) – I used a 12″ round cake pan, 2″ tall. (Two 9 x 13″ pans would also work!)
Spread potato mixture evenly over the meat mixture, broil until potatoes are as browned as you would like them.
Serve immediately, or cool to room temperature, cover with plastic wrap, and chill.