Preheat oven to 400 degrees and coat casserole dish with non-stick spray

Peel and cube the potatoes.  Cook in boiling water until soft.  Drain the water and mash the potatoes with milk and 2 tablespoons of butter.  Set aside

In a large skillet, brown the beef over medium heat.  When the meat is almost cooked through, add the chopped onions until soft and translucent.  Then add the garlic for about 30 seconds or until it becomes fragrant.  Also, add salt & pepper to taste.  Remove from the heat and let cool

In a separate saucepan, melt the remaining 2 tablespoons butter and stir in the flour.  Whisk together until dark brown.  This could take about 8-10 minutes.   Let cool

On medium heat, stir in the beef broth or stock, ketchup and browning & seasoning sauce.  Simmer until thick

Add the sauce to the ground beef and mix

Transfer meat to the casserole dish, top with the mashed potatoes and sprinkle the shredded cheese on top

Bake for 10-15 minutes or until the cheese is melted and the potatoes are browned.  Serve!