Preheat oven to 350°F (175°C).
Lightly grease a 10" cast iron skillet or baking dish.
Add 1 lb ground beef to the skillet, press evenly, season with salt & pepper.
Peel and thinly slice 4 potatoes, layer on top of the beef.
Sprinkle over 8 oz grated Colby Jack cheese.
In a bowl, whisk together: 1 can cream of chicken soup, 1 can cream of celery soup, ⅓ cup milk, ½ tsp all-purpose seasoning, and ½ tsp Worcestershire sauce.
Pour sauce over the cheese layer, spread evenly.
Cover tightly with foil; place on a baking sheet in the oven.
Bake for 90 minutes.
Remove foil, sprinkle ½ cup fried onions on top.
Broil for 2–3 mins until golden and crispy.
Let rest for 5–7 mins; garnish with green onions or parsley if desired.