In a large saucepan cook potatoes in water until tender about 15-20 minutes. Drain water thoroughly and mash with electric mixer. Add sour cream and milk and continue mixing. Add chicken broth 1 tablespoon at a time until potato mixture is light and fluffy. Stir in 1/2 cup of cheddar cheese, cover and set aside.
Meanwhile in a large ovenproof skillet brown the ground beef. When the ground beef is just a couple minutes short of being done add the onion, garlic and red pepper. Cook for an additional 2-3 minutes. Remove from heat and drain any fat. Stir in the pickles, oregano, basil and a few twists of your pepper mill. Return skillet to low heat and add the white American cheese, chicken broth and mustard. Cook, stirring gently until the cheese has melted.
Remove from heat. Using a large spoon or ice cream scoop the potatoes in mounds over the beef mixture. Bake for 15 minutes. Remove from oven and sprinkle with remaining 1/2 cup cheese and cook an additional 10 minutes turning the broiler on the last minute of cooking just to brown the potatoes a tad.